CN112459698B

CN112459698B - Foldable ladder

Info

Publication number: CN112459698B
Application number: CN202011109286.9A
Authority: CN
Inventors: M·I·基弗; A·A·考德威尔; N·L·施吕特
Original assignee: Core Distribution Inc
Current assignee: Core Distribution Inc
Priority date: 2014-12-02
Filing date: 2015-12-02
Publication date: 2022-01-11
Anticipated expiration: 2035-12-02
Also published as: CN112459698A; EP3227517C0; EP3227517B1; ES2963810T3; MX2017007137A; CA3130716A1; EP3227517A1; CA2968554C; WO2016090041A1; CA3130716C; CA2968554A1; CN107250479B; MX2022009716A; EP4273362A3; CN107250479A; EP4273362A2

Abstract

The present disclosure relates to a foldable ladder having a first ladder portion and a second ladder portion hingedly attached to the first ladder portion by a pair of hinge mechanisms. Each hinge mechanism is adapted to lock the first and second ladder portions such that the first ladder portion and the second ladder portion form an angle therebetween. The hinge mechanism has a displacement mechanism and a ladder angle selector coupled thereto to allow manual selection of the angle between the first and second ladder portions, and a locking pin to lock the first and second ladder portions in an angular position.

Description

Foldable ladder

This application is a divisional application of the patent application having application number 201580065774.5(PCT application number PCT/US2015/063518), application date 2015, 12-month and 02-day, entitled "foldable ladder".

Technical Field

The present application relates to a telescopic ladder having a stabilizer movable between an extended position and a retracted position.

Background

Ladders typically include rungs supported between stiles formed from a plurality of posts. In some cases, the ladder may be a telescoping ladder, and may be expanded to separate the posts from one another for extension of the ladder, or collapsed together for retraction of the ladder. These ladders often include mechanisms that allow the ladder to be folded for storage and unfolded during use.

Disclosure of Invention

Certain embodiments of the present invention include a foldable ladder comprising a first ladder section and a second ladder section hingedly attached to the first ladder section about a hinge axis by a pair of hinge mechanisms. Each hinge mechanism may lock the first and second ladder portions such that the first ladder portion and the second ladder portion form an angle therebetween. Each hinge mechanism has a shift mechanism that includes a shift pattern defined by a plurality of slots, each slot corresponding to an angular position of the first ladder portion relative to the second ladder portion. A displacement mechanism includes a selector pin that is displaceable in the displacement mode and is received by the slot to lock the second ladder portion in an angular position relative to the first ladder portion.

In some embodiments, the hinge mechanism includes a locking pin that is movable along its central axis radially away from and toward the hinge axis. The locking pin may be spring biased radially towards the hinge axis and may be rotatable about its central axis. The hinge mechanism comprises a plurality of recesses, each recess leading radially inwards from an end of the hinge member towards the hinge axis. The plurality of recesses may be angularly spaced about a hinge axis, wherein an angular position of the hinge axis about each recess corresponds to a predetermined angle between the first and second ladder sections. In these embodiments, each recess has a corresponding ladder angle opening, the opening having an opening shape. The opening shape may permit insertion of the locking pin therethrough when the locking pin is rotated about its central axis to a rotation in which the orientation of the locking pin cross-section substantially matches the opening shape. The opening shape may block insertion of the locking pin through the opening shape when the locking pin is rotated about its central axis to a rotation in which the orientation of the locking pin cross section does not substantially match the opening shape.

Certain embodiments comprise a method of folding a ladder. The method may comprise the steps of: providing a collapsible ladder; moving the selector pin away from the first slot to release the first and second ladder sections from the first angular position; displacing the selector pin in the displacement mode and proximate to the second slot; hingedly rotating one of the first and second ladder sections about a hinge axis to a second angular position; and securing the selector pin in the second slot and correspondingly securing the locking pin in the recess to lock the first and second ladder sections in the second angular position.

Certain embodiments of the present invention include a telescopic ladder comprising a first stile, a second stile, each having a plurality of posts disposed in a nested arrangement for relative axial movement between an extended position and a retracted position in a telescoping fashion along axes of the plurality of posts. A first column proximate a floor surface has a flange positioned in a hollow body of the first column coaxial with the axis of the plurality of columns. The ladder includes a plurality of rungs extending between a first stile and a second stile. Each ladder level is connected to a pillar of the first ladder frame and a pillar of the second ladder frame. A first stabilizer housing proximate to a floor surface on which the telescoping ladder is positioned is connected to the first and second posts.

In some embodiments, the telescopic ladder includes a first stabilizer connected to the first stabilizer housing. The first stabilizer is movable between an extended position and a retracted position, wherein in the extended position the first stabilizer extends out of the hollow body portion of the first stabilizer housing past the first stile in a direction substantially orthogonal to the axis of the plurality of posts. The first stabilizer is retracted into the hollow body portion of the first stabilizer housing in the retracted position. The first stabilizer includes a hollow body in sliding engagement with an inner surface of the first stabilizer housing, and a locking button adapted to protrude through an aperture defined on the first stabilizer housing to lock the first stabilizer in its extended position.

In certain embodiments, the locking button and aperture are coaxial with the axis of the plurality of posts in the extended position of the first stabilizer. In these embodiments, the flange may abut against a lock button protruding through the aperture of the first stabilizer housing due to the telescopic movement of the first post toward the first stabilizer housing. Abutment of the flange against the lock button urges the lock button away from the aperture and thereby unlocks the first stabilizer from its extended position and into a retracted position.

In some embodiments, the ladder is a collapsible telescopic ladder comprising a first ladder section, a second ladder section hingedly connected to the first ladder section such that the first and second ladder sections are rotatable about a hinge axis. At least one of the first and second ladder portions may have rungs comprising a pair of stabilisers adapted to extend through each of the first and second stiles of the first ladder portion and to retract into a hollow body portion of the first stabiliser housing in a direction substantially orthogonal to the axes of the plurality of posts.

Drawings

The following drawings illustrate specific embodiments of the present invention and therefore do not limit the scope of the invention. The drawings are not necessarily to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements.

FIG. 1A is a perspective view of a collapsible ladder locked in a first angular position according to an embodiment;

FIG. 1B is a perspective view of the collapsible ladder of FIG. 1A locked in a second angular position;

FIG. 2A is a perspective view of the collapsible ladder of FIG. 1A shown in a collapsed state locked in a third angular position;

FIG. 2B is a perspective view of the collapsible ladder of FIG. 2A shown in an extended state;

FIG. 2C is a close-up perspective view of portion "2C" of FIG. 2B;

FIG. 2D is a left side view of the foldable ladder of section "2D" of FIG. 1A, showing only the rungs of the first and second ladder sections;

FIG. 2E is a cross-sectional plan view of a portion of a ladder showing details of the connector assembly, according to an embodiment;

FIG. 3 is a perspective view of a hinge mechanism according to an embodiment;

FIG. 4A is a side view of the hinge mechanism of FIG. 3 with a selection collar removed from view for illustrating certain details of the hinge mechanism;

FIG. 4B is a side perspective view of the hinge mechanism of FIG. 3 shown in an unlocked state with the selection collar removed from view for illustrating certain details of the hinge mechanism;

FIG. 4C is a side view of the hinge mechanism shown in FIG. 4B with the second hinge member and the selection collar removed from view for illustrating certain details of the hinge mechanism;

FIG. 5 is a cross-sectional view of the hinge mechanism taken along line 5-5 shown in FIG. 3;

FIG. 6 is a detailed view of the hinge mechanism of FIG. 5 with certain components of the first hinge member removed from view to show certain details of the hinge mechanism;

FIG. 7 is a detailed perspective view of a locking pin, locking plate, selector pin, and biasing spring according to an embodiment;

FIG. 8A is a cross-sectional side view of the hinge mechanism of FIG. 5 with certain features removed from view for illustrating certain details of the hinge mechanism;

FIG. 8B is a close-up view of portion 8B of FIG. 8A;

FIG. 9A is a perspective view of a collapsible ladder locked in a first angular position according to an embodiment;

FIG. 9B is a perspective view of the collapsible ladder of FIG. 9A locked in a second angular position in a collapsed state;

FIG. 9C is a perspective view of the collapsible ladder of FIG. 9B shown in an extended state;

FIG. 9D is a perspective view of the collapsible ladder of FIG. 9A locked in a third angular position;

FIG. 10A is a close-up perspective view of a portion 10A of the ladder shown in FIG. 9A;

FIG. 10B is a perspective view of the ladder of FIG. 10A showing the stabilizer in the extended position;

fig. 10C is a perspective view of the ladder of fig. 10A showing the stabilizer in the extended position and the stabilizer in the retracted position;

FIG. 10D is a perspective view of the portion 10D shown in FIG. 10A;

FIG. 11A is an exploded perspective view of the ladder section illustrated in FIG. 10A, with first and second posts hidden from view to show certain internal details;

FIG. 11B is a cross-sectional front view of the portion of the ladder shown in FIG. 10B, wherein the cross-section is taken along plane 11B-11B;

FIG. 12 is a perspective view illustrating a first stabilizer housing and first and second air dampers with the stabilizer shown in a retracted state, according to an embodiment;

FIG. 13 is a perspective view showing the stabilizer of FIG. 12 shown in an extended state;

fig. 14 is a perspective view of a stabilizer according to an embodiment;

FIG. 15A is a right side view of the stabilizer of FIG. 14 with a cover removed to illustrate internal details;

FIG. 15B is a cross-sectional right side view of a portion of FIG. 10B taken along plane 15B-15B;

FIG. 16 is an exploded perspective view of the stabilizer of FIG. 14 shown in conjunction with a connector;

FIG. 17 is a close-up exploded view of portion 17 shown in FIG. 10B;

FIG. 18 is a front view of an air damper according to an embodiment; and

figure 19 is a perspective view of the air damper of figure 18.

Detailed Description

The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the invention. Examples of construction, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements employ examples known to those of ordinary skill in the art of the present invention. Those skilled in the art will recognize that many of the described examples have a variety of suitable alternatives.

Fig. 1A is a front perspective view of a ladder 10 according to some embodiments. Fig. 1B, 2A, and 2B are front perspective views of the ladder 10 according to some embodiments unfolded and locked at various angles from its folded position illustrated in fig. 1. In fig. 1B, the ladder 10 has been unfolded and locked at an angle 60 of about 30 degrees from its folded position in fig. 1A. In fig. 2A and 2B, the ladder 10 has been locked at an angle 60 of about 180 degrees. In fig. 2A, the upper section 12 of the ladder 10 is in a retracted/retracted state, while in fig. 2B, the upper section 12 of the ladder 10 is in an extended state. The ladder 10 illustrated in these views may have a first ladder section 14 and a second ladder section 16, each comprising two opposing stiles: a left stile 18 and a right stile 20, each stile being formed of a plurality of posts 22. According to the illustrated embodiment, each opposing post of each stile includes a rung 24 extending therebetween, with each rung 24 coupled to an opposing post on either end by a connector assembly 28. In some embodiments, the post 22 is formed of aluminum. Other materials are contemplated and within the scope of the present invention. The pillars 22 are illustrated as having a circular cross-section (when viewed along the longitudinal axis 40 of the pillars 22), and the pillars 22 may have a rectangular cross-section, such as those described in U.S. publication No. 2012/0267197a1, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety. Other cross-sections (e.g., square, oval, or polygonal shapes) are also contemplated. As will be described herein, in some embodiments, the posts 22 may be substantially hollow so as to allow the connector assembly 28 to fasten the step 24 to the posts on each of the right side stile 20 and the left side stile 18.

Figure 2C illustrates a close-up perspective view of rungs 24 of first ladder portion 14. Figure 2D illustrates a side view showing the rungs 24 of the first ladder section 14 and the rungs 24 of the second ladder section 16 when the ladder 10 is collapsed as shown in figure 14. In some embodiments, each step 24 includes a planar first surface 30 and a planar second surface 32 opposite the planar first surface 30. The first surface 30 of each rung 24 of the first ladder portion 14 defines a flat standing surface 34. At least one of the planar first and second surfaces of the second ladder portion 16 defines a planar standing surface 34. Referring back to fig. 2A-2B, when the ladder 10 is deployed for use, the first surface 30 of each rung 24 of the second ladder portion 16 has a flat standing surface 34, as shown in the close-up view of fig. 2C. However, when the ladder 10 is folded for storage or deployment to an angle other than about 180 degrees (e.g., as shown in fig. 1B), the first surface 30 of each rung 24 of the second ladder portion 16 may not face upward, and thus a flat standing surface 34 may be defined on the underside of the rung 24 when the ladder 10 is folded for storage or deployment to an angle other than 180 degrees. The flat standing surface 34 of each rung 24 of the first ladder portion 14 and the second ladder portion 16 may have a tread 36 defined therein to provide friction between the flat standing surface 34 and a contact surface of a user (e.g., a sole of a user's shoe). As will be described herein, the rungs may be substantially hollow so as to allow the connector assembly 28 to fasten the rungs 24 to the posts on each of the right side stiles 20 and the left side stiles 18. The steps may be extruded from aluminum, but other materials and manufacturing methods may be used.

Although fig. 2C and 2D illustrate steps 24 having a generally rectangular cross-section, other cross-sectional shapes of steps 24 are also contemplated. For example, the rungs 24 may have a parallelogram cross-section, such as those described in U.S. publication No. 2012/0267197a1, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety. Although the illustrated fig. 2C and 2D show a generally rectangular rung 24, at least a portion of the first surface 30 of the first ladder portion 14 and the second ladder portion 16 form an angle 60 with respect to the horizontal plane 42. In the illustrated embodiment, when the angled portion of the first surface 30 forms an angle θ with respect to the horizontal plane 42. The angle θ may be between about 5 degrees and 45 degrees (e.g., between 5 degrees and 20 degrees). These embodiments allow at least the angled portion 38 of the first surface 30 of the ladder 10 to be horizontal when the ladder 10 is rotated toward the vertical wall (e.g., against the wall at an angle) so that at least a portion of the vertical wall may be approximately horizontal during normal use. However, depending on the angle at which the ladder 10 abuts the vertical wall, the angled portion 38 may exceed or fall short of horizontal.

Referring back to fig. 2C, each step 24 is connected to a column of the plurality of columns 22 by a connector assembly 28. In some cases, the plurality of posts 22 are disposed in a nested arrangement for relative axial movement in a telescoping fashion such that the ladder 10 may be extended or retracted along the longitudinal axis 40 of the posts 22. Such telescoping ladders and various types of connector assemblies are described in detail in U.S. patent No. 8,387,753B2 and U.S. patent No. US6,883,645B2, both of which are assigned to the assignee of the present application, and the disclosure of each of which is hereby incorporated by reference in its entirety. In these telescoping ladders, the connector assembly 28 includes a release button 43 that is slidable along a front surface 44 of the rung 24 to unlock or selectively lock relative axial movement between two adjacent pillars 22 of the plurality of pillars 22, the front surface 44 of the rung 24 being substantially perpendicular to a plane 46 that is orthogonal to the longitudinal axis 40 of the plurality of pillars 22.

Fig. 2E illustrates a top cross-sectional view of a portion of the ladder taken along a plane parallel to the top surface of the ladder rung illustrating details of the connector assembly 28 according to some embodiments. The cross-sectional view of figure 2E shows all of the rungs of the ladder with the connector assembly 28. The connector assembly includes a collar portion 28a that surrounds the post 22 and contacts the peripheral surface of the outer post, and a step portion 28b that is inserted into the step 24. In the embodiment shown in fig. 2E, the connector assembly 28 includes a latching mechanism received in the step portion 28b that includes two

release buttons

43a and 43b and a pin 45. The release button 43a is slidable along the front surface 44 of the step and the release button 43b is slidable along the rear surface 47 of the step 24. In the embodiment of FIG. 2E, the pin 45 is disposed in an extended position, with the pin 45 extending into the aperture 29 defined on the connector assembly 28 and into the opening 41 on the post 22. In some embodiments of the invention, pin 45 is biased (e.g., by spring 49) to assume an extended position. When this is the case, the pin 45 can be selectively advanced to assume the retracted position by applying a sliding motion of the

button

43a or 43b in the direction 51. According to the illustrated embodiment, the pin 45 includes one or more through-holes 53 through which the shank 55 of each

button

43a, 43b may be inserted (e.g., by friction fit) for coupling the

buttons

43a, 43b to the pin 45 in a cooperative pattern. As is apparent from fig. 2E, the pin 45 may be retracted or extended by sliding the button 43a or the button 43b along the

respective surface

44 or 47 in the direction 51 as illustrated. Sliding movement of either button will also cause the other button to slide in direction 51 as there is a cooperative connection therebetween via pin 45. In some cases, each rung 24 of first ladder portion 14 and second ladder portion 16 may have a button slidable on front surface 44 and a button slidable on rear surface 47, as illustrated. Alternatively, either ladder section (first ladder section 14 or second ladder section 16) may have buttons on both the front surface 44 and the rear surface 47.

Referring back to fig. 1A, the foldable ladder 10 includes a pair of hinge mechanisms that hingedly connect the first ladder section 14 to the second ladder section 16. Fig. 3 illustrates a perspective view of the hinge mechanism 48, and fig. 4A-4B illustrate various detailed views of the hinge mechanism 48 according to some embodiments of the present invention. As seen in fig. 1A-2B and 3, the hinge mechanism 48 may fold the first ladder section 14 and the second ladder section 16 about a hinge axis 50. The hinge mechanism 48 may lock the first ladder section 14 and the second ladder section 16 such that the first ladder section 14 and the second ladder section 16 form an angle 60 therebetween. As best seen in fig. 1B, the angle 60 may be defined as the angle between the longitudinal axis 40 of the column 22 of the first ladder portion 14 and the longitudinal axis 40 of the column 22 of the second ladder portion 16. In fig. 1A, the first ladder section 14 and the second ladder section 16 form an angle 60 of about 0 degrees. In fig. 1B, the first ladder section 14 and the second ladder section 16 form an angle 60 of about 30 degrees. In fig. 2A-2B, the first ladder section 14 and the second ladder section 16 form an angle 60 of about 180 degrees.

Referring now to fig. 4A-4C, each hinge mechanism 48 includes a first hinge member 52 attachable to the first ladder section 14 and a second hinge member 54 attachable to the second ladder section 16. As seen in fig. 1B, the first hinge member 52 may be coaxially connected with the longitudinal axis 40 of the pillar 22 of the first ladder section 14 and the second hinge member 54 may be coaxially connected with the longitudinal axis 40 of the pillar 22 of the second ladder section 16. For example, as seen in fig. 1A, the first hinge members 52 of the left and right side hinge mechanisms are both connected to the uppermost pillars 56 (left and right side pillars 56) of the first ladder portion 14, and the second hinge members 54 of the left and right side hinge mechanisms are both connected to the uppermost pillars 58 (left and right side pillars 58) of the second ladder portion 16. The hinge mechanisms on the left and right sides shown in fig. 1A may be substantially similar. Alternatively, the hinge mechanism 48 on the right side may be a mirror image of the hinge mechanism 48 on the left side. The first hinge member 52 and the second hinge member 54 are rotatable relative to each other about the hinge axis 50. Because the first hinge member 52 and the second hinge member 54 are rigidly coupled to the first ladder section 14 and the second ladder section 16, rotation of the first hinge member 52 and the second hinge member 54 causes the first ladder section 14 and the second ladder section 16 to rotate relative to one another, and vice versa. The rotation of the first ladder section 14 and the second ladder section 16 is about the hinge axis 50 such that the first ladder section 14 and the second ladder section 16 and the first hinge member 52 and the second hinge member 54 form an angle 60 therebetween when rotated. At least a portion of the edge 62 of the second hinge member 54 may be semi-circular. Additionally, at least a portion of the edge 64 of the first hinge member 52 can be semi-circular. Other shapes of portions of the

edges

62, 64 are also contemplated, such as a semi-elliptical or other arcuate shape.

With continued reference to fig. 3 and 4A-4C, the hinge mechanism 48 includes a displacement mechanism 70. The displacement mechanism 70 may act as a selector and allow a user to select the angle 60 between the first ladder section 14 and the second ladder section 16. The displacement mechanism 70 includes a displacement pattern 72 defined by a plurality of

slots

74, 76, 78 peripherally positioned on the first hinge member 52. Each

slot

74, 76, 78 corresponds to an angular position of the first ladder section 14 relative to the second ladder section 16, and

adjacent slots

74, 76, 78 are separated by a distance 80 defined along a periphery of the first hinge member 52. As best seen in fig. 4A, the selector pin 82 is displaceable in the displacement mode 72 and is received by the

slots

74, 76, 78 at the first ends 84 of the

slots

74, 76, 78 to lock the second ladder portion 16 in an angular position relative to the first ladder portion 14. In the illustrated embodiment shown in fig. 4A and 4B, the displacement mechanism includes three

slots

74, 76, 78 that correspond to three angular positions at which the first ladder section 14 and the second ladder section 16 may be positioned. As shown in fig. 4C, the selector pin 82 may be released from the first end 84 and moved proximate to the second end 86 to release the first ladder portion 14 and the second ladder portion 16 from their locked positions. Once released, the first ladder portion 14 and the second ladder portion 16 may be rotated relative to each other to change the angle 60 therebetween.

As seen in fig. 4A-4C, the hinge mechanism 48 contains one or more safety indicators. The safety indicator may be a visual indicator, such as a flag or a color coded band, to indicate whether the first ladder section 14 and the second ladder section 16 are locked in the angular position. The safety indicator may be an audible "click" or tactile indicator to provide audible or tactile feedback to the user to indicate that the first ladder portion 14 and the second ladder portion 16 are securely locked in the angular position. In the embodiment illustrated in fig. 4A, the safety indicator provides a first visual indication 90 (e.g., a green strip or zone, or other indicia in the first zone 96) when the first ladder portion 14 and the second ladder portion 16 are locked in the angular position. In the embodiment illustrated in fig. 4B and 4C, the safety indicator provides a second visual indication 92 (e.g., a red strip or region, or other indicia disposed in the second region 98) when the first ladder section 14 and the second ladder section 16 are unlocked. Additionally, the ladder 10 may include other indicia (e.g., alphanumeric characters, images, symbols, etc.) to indicate the predetermined angle at which the first ladder portion 14 and the second ladder portion 16 may be positioned. For example, in the embodiment illustrated in fig. 4B, three markers 94 are symbolic representations of the angular positions of the ladder 10 indicating that the first ladder portion 14 and the second ladder portion 16 may be locked at about 0 degrees, about 30 degrees, and about 180 degrees. These markings 94 may also be positioned proximate to each

slot

74, 76, 78 to provide the user with information regarding how the first ladder portion 14 and the second ladder portion 16 will rotate the angle of rotation 60 when the selector pin 82 is positioned proximate to each

slot

74, 76, 78 (e.g., at or near the second end 86 thereof).

Referring now to fig. 5, in some embodiments, the hinge mechanism 48 includes a locking plate 100 positioned in the second hinge member 54 such that a center 110 of the locking plate 100 is concentric with the hinge axis 50. As seen in the cross-sectional view of fig. 5, the locking plate 100 may be bolted to the second hinge member 54 such that the hinge axis 50 coincides with the center 110 of the locking plate 100. Alternatively, the locking plate 100 may be connected to the second hinge member 54 such that it forms a friction fit with an inner surface (e.g., ribs) of the second hinge member 54 such that the center 110 of the locking plate 100 is concentric with the hinge axis 50. When coupled in this manner, the locking plate 100 is fixedly positioned in the second hinge member 54 and does not move or rotate relative to the second hinge member 54.

With continued reference to fig. 5, the locking plate 100 includes a plurality of

recesses

112, 114, 116. Each recess extends radially inward from an outer edge 118 of the locking plate 100 and toward the center 110 of the locking plate 100. Due to the concentric positioning of the center 110 of the locking plate 100 and the hinge axis 50, the

recesses

112, 114, 116 are thus each guided radially inwards from one end of the second hinge part 54 towards the hinge axis 50. The

recesses

112, 114, 116 are angularly spaced about the hinge axis 50 such that the angular position of each recess about the hinge axis 50 corresponds to the predetermined angle 60 between the first ladder section 14 and the second ladder section 16. In this position, the selector pin 84 is received in the

slots

74, 76, 78. For example, in an exemplary embodiment, each recess may be separated from another recess by an angle 119 corresponding to the angle 60 between the first ladder portion 14 and the second ladder portion 16. In such cases, the number of

recesses

112, 114, 116 corresponds to the number of positions in which the first ladder section 14 and the second ladder section 16 may be locked. In the illustrated embodiment, the locking plate 100 includes three

recesses

112, 114, 116: a first recess 112, a second recess 114, and a third recess 116. The first ladder portion 14 and the second ladder portion 16 may thus be locked in three angular positions, corresponding to the angle 119 between each of the

recesses

112, 114, 116. In operation, the first ladder section 14 and the second ladder section 16 may be rotated through an angle 60 corresponding to an angle 119 between two recesses (e.g., 112 and 114, or 112 and 116) and locked therein. As described above, the angle 60 between the first ladder portion 14 and the second ladder portion 16 may be between about 0 degrees and about 180 degrees. For example, the locking plate 100 in the illustrated embodiment includes three

recesses

112, 114, 116, and the first ladder section 14 and the second ladder section 16 may be locked in a first angular position, a second angular position, and a third angular position at angles of about 0 degrees, about 30 degrees, and about 180 degrees, respectively. Thus, in the illustrated embodiment shown in fig. 5, the angle 119 between the first and

second recesses

112, 114 is about 30 degrees, and the angle 119 between the first and

third recesses

112, 116 is about 180 degrees. Additional recesses corresponding to additional lockable configurations (e.g., at about 45 degrees, about 60 degrees, about 120 degrees, or other additional angles) of the first ladder portion 14 and the second ladder portion 16 are also contemplated.

Referring now to fig. 6, in some embodiments, the collapsible ladder 10 includes a locking pin 120 connected to the selector pin 82. The locking pin 120 has an elongated body disposed about a central axis 122 of the locking pin 120. As illustrated in fig. 6, the locking pin 120 moves in and out of the recesses (112, 114, 116) in a direction along its central axis 122 and is receivable by the recesses (112, 114, 116) of the locking plate 100. For example, the locking pin 120 is received by the first recess 112 to lock the first and second corner portions at a first angle 60 (e.g., 0 degrees), the second recess 114 to lock the first and second corner portions at a second angle 60 (e.g., 30 degrees), and the third recess 116 to lock the first and second corner portions at a third angle 60 (e.g., 180 degrees). As described above, the locking plate 100 may have any number of

recesses

112, 114, 116, and thus the first ladder section 14 and the second ladder section 16 may be locked in a corresponding number of angular positions. Referring back to fig. 5, the locking pin 120 is received in the second recess 114. Correspondingly, the selector pin 82 is received in the second slot 76. In the embodiment illustrated in fig. 5, the angle between the first ladder portion and the second ladder portion is about 30 degrees. Other angular positions are contemplated. For example, when the first ladder portion and the second ladder portion are locked at the angle 60 of about zero degrees, the locking pin 120 is fully received in the first recess 112 and the selector pin 82 is fully received in the slot 74. When the first and second ladder portions are locked at the angle 60 of about 180 degrees, the locking pin 120 is fully received in the third recess 116 and the selector pin 82 is fully received in the slot 78.

As shown in fig. 6 and 7, the locking pin 120 has a rectangular cross-section with an edge 121 along the length and an edge 123 along the width, although any non-circular cross-section is also contemplated. The locking pin 120 is mountable to the first hinge member 52 for radial movement along its central axis 122 away from and toward the hinge axis 50. As will be described below, the locking pin 120 is spring biased radially toward the hinge axis 50 by a biasing spring 124. The locking pin 120 is rotatable about its central axis 122 such that the cross-sectional shape of the locking pin 120 is aligned with the shape of the recesses (112, 114, 116) on the locking plate 100.

With continued reference to the embodiment illustrated in fig. 6 and 7, the locking pin 120 has an aperture 126 in which the selector pin 82 is received. The locking pin 120 and the selector pin 82 are thus coupled such that they move in a cooperative manner as will be described below. In the illustrated embodiment, the locking pin 120 and the selector pin 82 are coupled such that the central axis 122 of the locking pin 120 is located transversely at an angle 60 (e.g., 90 degrees) relative to the axis 128 of the selector pin 82. Other angles between the locking pin 120 and the axis of the selector pin 82 are also contemplated. Referring back to fig. 5 and with continued reference to fig. 6, the selector pin 82 and the locking pin 120 may be coupled to one another such that the locking pin 120 moves into the recess (112, 114, 116) of the locking pin 120 when the selector pin 82 moves into the

slots

74, 76, 78 of the shift mode 72. Additionally, the coupling between the selector pin 82 and the locking pin 120 may be such that the locking pin 120 moves away from the recess (112, 114, 116) of the locking plate 100 when the selector pin 82 moves away from the

slots

74, 76, 78 of the shift pattern 72. While fig. 5 and 6 illustrate the locking pin 120 in its position received by the recess (112, 114, 116) of the locking plate 100, fig. 7 illustrates the locking pin 120 in its position retracted away from the recess of the locking plate 100. As seen in fig. 7, the locking pin 120 may be spring biased radially toward the hinge axis 50 by a biasing spring 124. When it is fully retracted away from the recess of the lock plate 100, the locking pin 120 may abut against the receptacle 130 when the locking pin 120 is retracted away from the recess (112, 114, 116) of the lock plate 100. As previously described, the first ladder portion 14 and the second ladder portion 16 may rotate relative to each other about the hinge axis 50. Rotation of the first ladder portion 14 and the second ladder portion 16 relative to each other may position the locking pin 120 proximate to the recess (e.g., at the ladder angle opening 132). Once the angle 60 between the first ladder section 14 and the second ladder section 16 is adjusted to correspond to the angle 119 between any two of the recesses (112, 114, 116) of the locking plate 100, the locking pin 120 is brought close to the recess (112, 114, 116) and extends into the recess due to the spring action from the spring received in the receptacle 130.

As previously described, the engagement between the locking pin 120 and the selector pin 82 allows the locking pin 120 to be fully received into a recess (e.g., the second recess 114 shown in fig. 5) to lock the first and

second ladder sections

14, 16 in an angular position, and fully retracted from the recesses (112, 114, 116) to release the first and

second ladder sections

14, 16 from the angular position. When the locking pin 120 is fully received in the recess, the integrated length of the recess is occupied by at least the first end 134 of the locking pin 120, as seen in fig. 5 and 6. In this position, the selector pin 82 is received in the

slots

74, 76, 78 (e.g., the second slot 76 as shown in fig. 5) such that the selector pin 82 rests in the first ends 84 of the

slots

74, 76, 78. In the fully received position, the first ladder section 14 and the second ladder section 16 are locked relative to each other and the angle 60 therebetween is fixed. When the locking pin 120 is fully released from the recess (e.g., the second recess 114 as shown in fig. 7), the second end 136 of the locking pin 120 seats against the receptacle 130. In the fully released position, the first end 134 of the locking pin 120 is almost fully retracted from the recess. Correspondingly, the selector pin 82 moves to the second end 86 of the

slot

74, 76, 78 (e.g., the second slot 76 best seen in fig. 5). In the fully released position, the first ladder section 14 and the second ladder section 16 may be rotated and the angle 60 therebetween may be changed. Prior to changing the angle 60 between the first ladder portion 14 and the second ladder portion 16, the selector pin 82 may be positioned proximate to another

slot

74, 76, 78 (e.g., the first slot 74 or the third slot 78 shown in fig. 5). When the first ladder section 14 and the second ladder section 16 are rotated to a desired angular position, the locking pin 120 is received by the other recess (e.g., the first recess 112 or the third recess 116) and the selector pin 82 is received by the first end 84 of the

other slot

74, 76, 78 (e.g., the first slot or the third slot 78).

Referring now to fig. 8A and 8B, the locking pin 120 may be shaped and oriented such that the locking pin 120 abuts against the edge 62 of the second hinge member 54 when the first ladder section 14 and the second ladder section 16 are angled at any angle 60 other than a plurality of predetermined angles. As seen from the close-up view of fig. 8B, each recess has a corresponding ladder angle opening 132 defined in the edge 62 of the second hinge member 54. Each ladder angle opening 132 has an opening shape. The opening shape may permit insertion of the locking pin 120 therethrough when the locking pin 120 is rotated about its central axis 122 to a rotation in which the orientation of the locking pin 120 cross-section substantially matches the opening shape (e.g., as shown in fig. 5 and 6). As seen in fig. 8A and 8B, the opening shape of ladder angle opening 132 may block insertion of locking pin 120 therethrough when locking pin 120 is rotated about its central axis 122 to a rotation in which the orientation of the locking pin 120 cross-section does not substantially match the opening shape. As shown in fig. 8A and 8B, edge 121 along the length and edge 123 along the width do not match the opening shape of ladder angle opening 132 of recess 112, thereby preventing locking pin 120 from entering recess 112. In the illustrated embodiment, each recess is disposed radially inward toward the hinge axis 50 along a radial line 138. When the locking plate 100 is positioned concentrically with the hinge axis 50, the intersection of the center 110 of the locking plate and the radial line 138 coincides. The

recesses

112, 114, 116 are rectangular and the ladder angle opening shape allows passage of a locking pin 120 having a rectangular cross section oriented such that the central axis 122 of the locking pin 120 is in line with the radial line 138 of the recess, and the locking pin 120 is rotated about its central axis 122 such that the cross section of the locking pin 120 is aligned with the opening shape of the ladder angle opening 132.

Referring back to fig. 5 and 6, the locking pin 120 may be rotated about its central axis 122 by the selector collar 142. As described above, each recess has a ladder angle opening 132 that allows the locking pin 120 to pass through the opening as the locking pin 120 is rotated about its central axis 122 so as to match the opening shape. In these circumstances, the ladder angle selector permits manual selection of a desired angle 60 between the first ladder section 14 and the second ladder section 16. In some embodiments, the ladder angle selector is a selection collar 142 that is slidably engaged with the first hinge member 52. The selector collar 142 is rigidly engaged with the selector pin 82. The selector pin 82, in turn, is rigidly engaged with the locking pin 120, allowing the selector collar 142 to manipulate movement and rotation of the locking pin 120. As shown for example in fig. 5, the selection collar 142 may slide along a collar axis 144 against the first hinge member 52 in a direction illustrated by arrow "d" defined generally parallel to the collar axis 144 and the central axis 122 of the locking pin 120. As the selection collar 142 slides along direction "d", the selector pin 82 moves along with the selection collar 142 and out of the second slot 76 in direction "d" toward the second end 86 of the second slot 76 (best illustrated in fig. 4C). Also, referring back to fig. 5, the locking pin 120 moves in a direction "d" parallel to its central axis 122 and radially outward from the second recess 114. When the selector pin 82 rests against the second end 86 of the second slot 76, the second end 136 of the locking pin 120 abuts against the receptacle 130 (best seen in fig. 7).

Referring back to fig. 4A-4C and 5, when the selector collar 142 is moved in the direction "d" such that the selector pin 82 is moved to the second end 86 of the second slot 76, the first ladder section 14 and the second ladder section 16 are not locked in the angular position. Thus, as described above, the second region 98 previously hidden under the selector collar 142 becomes visible to the user when the first ladder section 14 and the second ladder section 16 are locked to indicate that the first ladder section 14 and the second ladder section 16 are not securely locked. Once the angle 60 between the first ladder section 14 and the second ladder section 16 is adjusted to the desired angle, the locking pin 120 moves in the direction "f" as it is spring biased toward the hinge axis 50. The direction "d" may be opposite to the direction "f". The selector pin 82 moves in the direction "f" and proximate to the first end 84 of the second slot 76. During this movement, the selection collar 142 also moves in the direction "f" due to the rigid coupling between the selection collar 142, the locking pin 120 and the selector pin 82. The locking pin 120 is received in the recess (112, 114 or 116) and the selector pin 82 is received in the

slot

74, 76, 78, thereby preventing any relative rotational movement between the first and

second hinge members

52, 54 and the first and

second ladder sections

14, 16 connected thereto about the hinge axis 50. As the selector collar 142 is moved in the direction "f", the first region 96 previously hidden under the selector collar 142 becomes visible to the user when the first ladder section 14 and the second ladder section 16 are unlocked to indicate that the first ladder section 14 and the second ladder section 16 are securely locked.

With continued reference to fig. 4A-4C and 5, the selection collar 142 is rotatable relative to the first hinge member 52 about a collar axis 144. As the selection collar 142 is rotated (e.g., in the direction "e" about the collar axis 144 illustrated in fig. 5), the selector pin 82 moves along the displacement pattern 72 defined on the first hinge member 52. For example, the selection collar 142 may move until the selection pin moves adjacent to the third slot 78. As the selection collar 142 rotates about the collar axis 144 relative to the first hinge member 52, the rigid coupling between the selector pin 82 and the locking pin 120 transmits rotational movement of the selection collar 142 and rotates the locking pin 120 about its central axis 122. When the selection collar 142 is rotated sufficiently to bring the selector pin 82 proximate to the third slot 78 (e.g., at the second end 86 of the third slot 78), the locking pin 120 is rotated about its central axis 122 such that its cross-section matches the opening shape of the third recess 116. Such manual manipulation may allow a user to manually select a desired angle 60 from a plurality of predetermined angles between the first ladder section 14 and the second ladder section 16.

In use, a user may deploy the ladder 10 from its angular position during storage (e.g., the first ladder portion 14 and the second ladder portion 16 form an angle 60 of about 0 degrees, as illustrated in fig. 1A). Referring to fig. 4A-4C, a user may displace the selection collar 142 in direction "d" and rotate the selection collar 142 in direction "e" until the selection pin is proximate the second end 86 of the

other slot

74, 76, 78. The rotational movement of the selection collar 142 rotates the locking pin 120 about its central axis 122 such that the cross section of the locking pin 120 matches the ladder angle opening 132 of the recess (112, 114, 116). The user may then rotate the first ladder portion 14 and the second ladder portion 16 relative to one another to a desired angle 60 (selected from a predetermined angle at which the first ladder portion 14 and the second ladder portion 16 may be locked). Once the desired angle 60 is reached, the locking pin 120 is automatically pushed into the recess (112, 114 or 116) as the locking pin 120 is spring biased in direction "f" towards the hinge axis 50. The selector pin 82 and the selector collar 142 also move in the direction "f". The first ladder portion 14 and the second ladder portion 16 are locked in a desired angular position, and the selector pin 82 rests in the first end 84 of the

slots

74, 76, 78 corresponding to the desired angular position. The first ladder section 14 and the second ladder section 16 may not be rotated further until the locking pin 120 is released from the recess (112, 114 or 116) by moving the selection collar 142 in direction "d" and repeating the above steps.

Embodiments of the collapsible ladder described herein may allow a user to collapse the ladder for storage to minimize floor space, as well as to expand it and securely lock it at multiple angles. The embodiments of the collapsible ladder described herein are safe and easy to use.

Figure 9A is a front perspective view of a ladder 210 according to some embodiments. Figures 9B-9D are front perspective views of the ladder 210 according to some embodiments deployed from its collapsed position illustrated in figure 9A and locked at various angles. In fig. 9B and 9C, the ladder 210 has been unfolded and locked at an angle of about 180 degrees from its folded position in fig. 9A. In fig. 9D, the ladder 210 has been locked at an angle of about 30 degrees. In fig. 9B, the upper portion 222 of the ladder 210 is in a retracted state, while in fig. 9C, the upper portion 222 of the ladder 210 is in an extended state.

Referring now to fig. 9A, the telescopic ladder 210 includes a first stile 214 and a second stile 216 (e.g., a left stile and a right stile as illustrated in fig. 9A). The first and second stiles each have a plurality of posts 218 disposed in a nested arrangement for relative axial movement between an extended position and a retracted position in a telescoping fashion along an axis 220 of the plurality of posts 218. For example, in fig. 9A, the upper portions 222 of the ladder 210 are shown in a retracted position, in which the posts 218 nest within each other in a telescoping fashion along the axis 220 of the posts 218, and in fig. 9D, the upper portions 222 of the ladder 210 are shown in an extended position.

As seen in fig. 9A, the ladder 210 includes a plurality of rungs 224 extending between the first stiles 214 and the second stiles 216. Each step 224 may be connected to a leg 218 of first stile 214 and a leg 218 of second stile 216. As shown in fig. 9A, each step 224 may be connected to a post 218 by a connector assembly 226. With continued reference to fig. 9A, in some cases, each step 224 includes a planar first surface 228 and a planar second surface 230 opposite the planar first surface 228. The first surface 228 of each rung 224 of the first ladder portion 250 defines a flat standing surface 232. At least one of the planar first surface 228 and the planar second surface 230 of the second ladder portion 254 defines a planar standing surface 232. Referring to fig. 9B and 9C, the first surface 228 of each rung 224 of the second ladder portion 254 has a flat standing surface when the ladder 210 is deployed for use. However, when the ladder 210 is folded for storage or deployment to an angle other than about 180 degrees (e.g., as shown in fig. 9A or 9D), the first surface 228 of each rung 224 of the second ladder portion 254 may not face upward, and thus a flat standing surface 232 may be defined on the underside of the rung 224 when the rung 224 is folded for storage or deployment to an angle other than 180 degrees. The flat standing surface 232 of each rung 224 of the first and

second ladder portions

250, 254 may have a tread 234 defined therein to provide friction between the flat standing surface and a contact surface of a user (e.g., the sole of a user's shoe). As will be described herein, the rungs 224 may be substantially hollow so as to allow the connector assembly 226 to fasten the rungs 224 to the posts 218 on each of the right and left side stiles. The steps 224 may be extruded from aluminum, but other materials and manufacturing methods may be used.

Although fig. 9A-9D illustrate the steps 224 having a generally rectangular cross-section, other cross-sectional shapes of the steps 224 are also contemplated. For example, the rungs 224 may have a parallelogram cross-section, such as those described in U.S. publication No. 2012/0267197a1, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety. Although the illustrated fig. 9A-9D show a generally rectangular rung 224, as best seen in fig. 10D, at least a portion 238 of the first surface 228 of the first and

second ladder portions

250, 254 may form an angle θ relative to the horizontal plane 242. In the illustrated embodiment, when the angled portion 238 of the first surface 228 is angled relative to a horizontal plane (not shown). The angled portion 238 may form an angle of between about 5 degrees and 45 degrees (e.g., between 5 degrees and 20 degrees) with respect to the horizontal plane 242. These embodiments allow at least an angled portion 238 of the first surface 228 of the rungs 224 to be horizontal when the ladder 210 is rotated toward a vertical wall (e.g., against the wall at an angle), such that at least a portion 238 of the rungs 224 may be approximately horizontal during normal use. However, depending on the angle at which the ladder 210 abuts the vertical wall, the angled portion 238 may exceed or fall short of horizontal.

In some embodiments, the post 218 is made of aluminum. Other materials are contemplated and within the scope of the present invention. The post 218 is illustrated as having a circular cross-section (when viewed along an axis 220 of the post 218). However, the posts 218 may have a rectangular cross-section, such as those described in U.S. publication No. 2012/0267197A1, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety. Other cross-sections (e.g., square, oval, or polygonal shapes) are also contemplated. The post 218 may be substantially hollow to receive another post 218 from above. Additionally, the step 224 may be substantially hollow such that a pair of latch assemblies (not shown) may be received in the hollow step 224.

As described above, the steps 224 are connected to the posts 218 by a plurality of connector assemblies 226. The connector assembly 226 may have a latch assembly received in a hollow portion of each step 224 to unlock or selectively lock relative axial movement between adjacent posts 218. Such connector assemblies 226 are described in U.S. patent No. 8,387,753B2 and U.S. patent No. US6,883,645, both of which are assigned to the assignee of the present application, and the disclosures of each of which are hereby incorporated by reference in their entirety. Each latch assembly has a release button 246 that can be manually actuated to unlock the selectively locked relative axial movement between two adjacent posts 218. In the embodiment shown in fig. 9A, the release button can be slid inward (e.g., by a user's thumb) along the front surface 248 of the step 224 to unlock its respective latch assembly. Thus, when the release buttons on both the right and left sides of the step 224 are actuated, axial movement of the adjacent post 218 is permitted. Gravity may cause these posts 218 and their rungs 224 to collapse downward to assume a position similar to the rungs 224 shown in the collapsed portion of the ladder 210 shown in figure 9A.

In some cases, the ladder 210 may include a first ladder portion 250 and a second ladder portion 254 coupled to each other in an articulated fashion. For example, the ladder 210 may be collapsible such that the first ladder section 250 and the second ladder section 254 form a first angle 258 therebetween. The first angle 258 may be equal to between about zero degrees and about 180 degrees. In fig. 9A, the first angle 258 is about zero degrees. In fig. 9B and 9C, the first angle 258 is about 180 degrees. In fig. 9D, the first angle 258 is about 30 degrees. Each of the first and

second ladder portions

250, 254 may have first and

second stiles

214, 216 having a plurality of posts 218 and a plurality of rungs 224 extending between the posts 218. The first ladder section 250 and the second ladder section 254 may be locked in various angular positions by hinge mechanisms known in the art. An exemplary hinge mechanism 260 is described and illustrated in co-pending U.S. application No. 14/557,944, entitled Foldable ladder (Foldable ladder), which is assigned to the assignee of the present application and filed on 12/2/2014, the disclosure of which is hereby incorporated by reference in its entirety.

Referring now to fig. 10A and 10B, first stile 214 includes first post 264 and second stile 216 includes second post 268. The first and second posts 218 each have a hollow body. The first and second posts 218 may be connected to a first stabilizer housing 270. The first stabilizer housing 270 and the first and second posts 218 may be proximate to a floor surface 272 on which the ladder 210 is positioned during use. The first stabilizer housing 270 and the first and second posts 218 may be coupled by a pair of connector assemblies 226 as described above. Alternatively, the connector 274 may fixedly connect the first and second posts 218 to the first stabilizer housing 270. The connector 274 may have a connector opening 276 (best shown in fig. 16, for example) for receiving the first stabilizer housing 270. The connector 274 additionally receives the first and second posts 218 in its inner surface 278. The first and second posts 218 form a friction fit with the inner surface 278 of the connector 274.

Referring back to fig. 10A and 10B, the ladder 210 may include a first stabilizer 280 and a second stabilizer 282 connected to the first stabilizer housing 270. The first stabilizer 280 and the second stabilizer 282 are each movable between an extended position and a retracted position. The first stabilizer 280 and the second stabilizer 282 may be substantially similar, but the right side stabilizer 282 may be a mirror image of the left side stabilizer 280 (about the axis 220 of the post 218). The first stabilizer 280 and the second stabilizer 282 are slidably movable with respect to the first stabilizer housing 270. In some cases, the first stabilizer 280 and the second stabilizer 282 may extend independently. For example, the first stabilizer 280 may extend while the second stabilizer 282 contracts, and vice versa, as illustrated in fig. 10C. As seen in fig. 10B and 10C, the first and

second stabilizers

280, 282 are retractable into the hollow body portion 286 of the first stabilizer housing 270 in a retracted position. In the extended position, the first and

second stabilizers

280, 282 extend out of the hollow body portion 286 of the first stabilizer housing 270 past one of the first and second stiles in a direction substantially orthogonal to the axes 220 of the plurality of posts 218.

Referring now to fig. 11A-11B and 12, the first stabilizer housing 270 has an aperture 290 defined coaxially with the axis 220 of the plurality of posts 218. As shown in fig. 13, each of the first and

second stabilizers

280, 282 has a locking button 294 that can protrude through an aperture 290 defined on the first stabilizer housing 270 in the extended position to lock the

stabilizers

280, 282. The locking button 294 may be generally in a depressed position when the first and

second stabilizers

280, 282 are collapsed and abutted against the inner surface 296 of the first stabilizer housing 270, and proximate to a centerline 310 of the first stabilizer housing 270 through which the locking button may protrude when the first and

second stabilizers

280, 282 are in the collapsed position. When the first and

second stabilizers

280, 282 are pulled out to the extended position, the locking button remains depressed and abuts against the inner surface 296 of the first stabilizer housing 270. Upon encountering the aperture 290, the locking button protrudes through the aperture and thereby locks the first and

second stabilizers

280, 282 and prevents them from slidably moving relative to the first stabilizer housing 270. When the locking buttons protrude through the apertures 290, the locking buttons lock the

stabilizers

280, 282 in the extended position. These configurations may be used to improve the stability of the ladder 210 by allowing the center of gravity of the ladder 210 to fall within the footprint of the ladder 210.

Referring back to fig. 11A-11B, the first and second posts 218 each have a flange 320 positioned in the hollow body of the first and second posts 218 coaxially with the axis 220 of the plurality of posts 218. Fig. 12 illustrates a close-up perspective view of the flanges of the first and second posts 218 (not illustrated in fig. 12). As seen in fig. 11A-11B and 12, the flanges 320 of the first and second posts 218 may depress the locking button 294 away from the aperture 290, thereby releasing the first and

second stabilizers

280, 282 from their locked positions, whereupon the first and

second stabilizers

280, 282 move generally inwardly into the hollow body portion 286 of the first stabilizer housing 270. The flange may be positioned and oriented in the first and second posts 218 such that when a post (e.g., post 370 or post 380 shown in fig. 10A) over each of the first and

second posts

264 and 268 nests therein, the flange is urged in a direction toward the first stabilizer housing 270 (e.g., from distance "a" to distance "B" shown in fig. 11B). Referring to fig. 11A-11B, due to the telescoping movement of the first post 264 toward the first stabilizer housing 270, the flange 320 abuts against the locking button 294 protruding through the aperture 290 of the first stabilizer housing 270, the locking button 294 being pushed away from the aperture 290, unlocking the first stabilizer 280 from its extended position and moving it into a retracted position.

Fig. 14 is a perspective view of

stabilizers

280, 282 according to an embodiment of the present invention. Fig. 15A is a side view of the

stabilizers

280, 282 of fig. 14 with the end cap 330 removed. As seen in fig. 14 and 15A, the

stabilizers

280, 282 have a generally hollow body portion having a length "L1" equal to about half the length "L2" of the first stabilizer housing 270. For example, both the first stabilizer 280 and the second stabilizer 282 shown in the above embodiments may have a length L1, and the first stabilizer housing 270 may have a length L2, allowing the first stabilizer 280 and the second stabilizer 282 to abut against each other when collapsed. The length of the

stabilizers

280, 282 may be measured from the first end 332 to the second end 334 of the

stabilizers

280, 282, and may not include the end cap 330 of any other additional cap of the

stabilizer

280, 282. Likewise, the length of the first stabilizer housing 270 may be the end-to-end length of the main body portion of the first stabilizer housing 270. The

stabilizers

280, 282 have a parallelogram cross-section to facilitate sliding engagement with the first stabilizer housing 270 (also having a parallelogram cross-section, as shown in fig. 15B). Referring back to fig. 14 and 15A, the first surface 340 of the

stabilizers

280, 282 is substantially planar and the second surface 342 of the

stabilizers

280, 282 has one or more recessed tracks 344. First surface 340 and second surface 342 are substantially parallel and opposite each other and form an angle "a" with respect to horizontal plane 242. When positioned in first stabilizer housing 270, first surface 340 forms a top surface and second surface 342 forms bottom surface 212. The

stabilizers

280, 282 also have a third surface 346 and a fourth surface 348 that form the parallelogram shape of the

stabilizers

280, 282. As noted above, other shapes of the

stabilizers

280, 282 are also contemplated, corresponding to the shape of the first stabilizer housing 270 (e.g., rectangular). Referring to fig. 15A and 15B, a connecting member 350 connects the

stabilizers

280, 282 to the hollow body portion 286 of the first stabilizer housing 270. For example, the attachment member 350 is a lag bolt or screw that rests in a recessed portion of the track of the

stabilizers

280, 282 and forms a friction fit therewith. One or more ends of the connecting member 350 may rest against the inner surface 296 of the first stabilizer housing 270 and facilitate sliding movement of the

stabilizers

280, 282 relative to the first stabilizer housing 270. As mentioned above, the locking button 294 extends past the first surface 340 of the stabilizers 280, 282 (e.g., out of the aperture 290, best shown in fig. 16). The locking button 294 may be spring biased by the clip 360 to protrude out of the aperture 352 of the

stabilizers

280, 282, and thus out of the aperture 290 of the first stabilizer housing 270. An end 364 of the clip 360 is received by the second surface 342 of the stabilizers 280, 282 (e.g., via a slot, not shown), and an opposite end 362 of the clip 360 is received by a slot 366 on the first surface 340 of the

stabilizers

280, 282. The

stabilizers

280, 282 may also have an end cap 330 having a cross-sectional area greater than the cross-sectional area of the hollow body portion 286 of the first stabilizer housing 270. The end cap 330 thus does not collapse into the first stabilizer housing 270 when the

stabilizers

280, 282 are collapsed. These embodiments facilitate manual access to the

stabilizers

280, 282 to extend them from their retracted positions. In addition to the end cap 330, the

stabilizers

280, 282 may also have an additional cap 368 positioned proximate the centerline 310 of the first stabilizer housing 270 and within the hollow body portion 286 of the first stabilizer housing 270.

As mentioned above, and referring now to fig. 17, the locking buttons of the

stabilizers

280, 282 may be actuated by flanges positioned in the first and second posts 218 due to nested telescopic movement (not shown in fig. 17) of the plurality of posts 218 into the first and second posts 218. Fig. 17 illustrates a third post 370 positioned above the first post 264. Likewise, fourth post 380 may be positioned above second post 268 (best seen in fig. 10A). Referring back to fig. 17, a third post 370 may be nested within the first post 264 and extend therefrom along the axis 220 of the plurality of posts 218. In some cases, each column may include an air damper 200 positioned coaxially with an axis 220 of the column to limit relative axial movement of the plurality of columns 218. In the illustrated embodiment, the air damper 200 covers the bottom peripheral edge 210 of the third column 370 to restrict air flow through the third column 370. The example air damper 200 is described in U.S. publication No. 2012/0267197a1, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety. As illustrated, the flange 320 may extend from a bottom surface 412 of the first air damper 400 positioned within the first column 264 of the first stile 214. As seen in fig. 17, the first air damper 400 is coaxial with the locking button 294 of the first stabilizer 280 when the locking button 294 protrudes through the aperture 290 of the first stabilizer housing 270 in the extended position.

Referring now to fig. 18 and 19, the air dampers 400 can each have a tab 414 defined on a peripheral surface thereof to facilitate insertion into the third column 370 and prevent removal of the air dampers 400 from the third column 370. The tab 414 has a tapered leading edge 416 that facilitates engagement with a corresponding opening 418 of the third post 370, and an upstanding trailing edge 420 that prevents removal of the tapered tab 414 from the third post 370. The air damper 400 is coupled to the third post 370 such that a tab of the air damper 400 protrudes through a corresponding opening of the third post 370 (best seen in fig. 17). Air damper 400 may be positioned such that the opening is proximate to the bottom peripheral edge of third column 370. Air damper 400 is coupled to third post 370 such that nested movement of third post 370 toward first post 264 moves flange 320 of air damper 400 toward aperture 290 of first stabilizer housing 270. As additional post 218 descends from above toward first post 264, air damper 400 moves even closer to first stabilizer housing 270 until flange 320 abuts against locking button 294 protruding through aperture 290. When the third post 370 is fully nested within the first post 264, the flange 320 of the first air damper 200 can then push the lock button 294 away from the aperture 290 and collapse the first stabilizer 280. Air damper 400 may also have a recessed portion 422 on its peripheral surface 410. The recessed portion 422 may receive a locking pin 430 (as shown in fig. 17) that locks the first and third posts 218 to prevent relative axial movement therebetween.

While the embodiments have been described above with respect to one half of the collapsible ladder 210 (e.g., the first ladder portion 250), the

stabilizers

280, 282 of the second ladder portion 254 are substantially similar to those of the first ladder portion 250. For example, the second ladder portion 254 may include a second stabilizer housing 440 having a pair of

stabilizers

280, 282 extending through each of the first stiles and the second stiles of the second ladder portion 254 in a direction substantially orthogonal to the axis 220 of the plurality of posts 218 and retracting into the hollow portion of the second stabilizer housing 440. The second stabilizer housing 440 may be proximate to the floor surface 272 when the first ladder portion 250 and the second ladder portion 254 form an angle between, for example, about zero degrees and about 60 degrees (e.g., 0 degrees as illustrated in fig. 9A and 30 degrees as illustrated in fig. 9D), while the second stabilizer housing 440 is distal from the floor surface 72 when the first ladder portion 250 and the second ladder portion 254 form an angle greater than 90 degrees (e.g., 180 degrees as illustrated in fig. 9B and 9C). The

stabilizers

280, 282 of the second ladder portion 254 may be retracted into the hollow portion of the second stabilizer housing 440 when the plurality of posts 218 are nested within one another in a telescoping fashion such that the ladder 210 is retracted into a retracted position (e.g., as seen in fig. 9A and 9B), and wherein the

stabilizers

280, 282 of the second ladder 210 portion may extend out of the second stabilizer housing 440 when the plurality of posts 218 are extended in a telescoping fashion (e.g., as seen in fig. 9C and 9D).

In use, as the posts 218 of the first ladder section 250 and the second ladder section 254 are extended, the flange 320 moves away from the apertures 290 of the first stabilizer housing 270 of the first ladder section 250 and the second stabilizer housing 440 of the second ladder section 254. The

stabilizers

280, 282 of the first and

second ladder portions

250, 254 extend out of the first and

second stabilizer housings

270, 440, respectively, until the locking button protrudes through the aperture in line with the axis 220 of the post 218. The first ladder section 250 and the second ladder section 254 may be locked in a desired angular position. During storage, the ladder 210 may be collapsed and the

stabilizers

280, 282 may be retracted. To collapse the

stabilizers

280, 282, the first and

second ladder portions

250, 254 may first be unlocked from the desired angular position. The posts 218 of each of the first and

second ladder portions

250, 254 may then be collapsed until the third post 370 is fully nested inside the first post 264 and the fourth post 380 is fully nested inside the second post 268. When third and fourth posts 218 are fully nested within first and second posts 218, flanges 320 of air dampers 400 of third and fourth posts 218 abut against apertures 290 and locking buttons 294 projecting therethrough. The flange 320 pushes the locking buttons 294 inward into the hollow portion of the respective stabilizer housing (e.g., the first stabilizer housing 270 and the second stabilizer housing 440) and thereby retracts the

stabilizers

280, 282 for storage.

Certain embodiments of the telescopic ladder 210 illustrated herein may improve safety by stabilizing the ladder 210 during use. For example, some embodiments of the telescoping ladder 210 having the

stabilizers

280, 282 extending therefrom ensure that the center of gravity of the ladder 210 always falls within the horizontal extent (e.g., footprint) of the ladder 210 during use, thereby minimizing or eliminating any moment that may tip the ladder 210 over during operation. Additionally, the

stabilizers

280, 282 may be collapsed during storage, thereby facilitating a compact footprint for the ladder 210 when not in use. Further, collapsing the posts 218 of the ladder 210 automatically collapses the

stabilizers

280, 282, thereby providing ease of use.

Accordingly, embodiments of a ladder are disclosed. Although embodiments of the present invention have been described in considerable detail with reference to certain disclosed embodiments, the disclosed embodiments are presented for purposes of illustration and not limitation, and other embodiments are possible. Those skilled in the art will appreciate that various changes, adaptations, and modifications may be made without departing from the spirit of the invention.

Claims

1. A foldable ladder, comprising:

a first ladder section;

a second ladder portion hingedly attached to the first ladder portion, each of the first and second ladder portions comprising

The first ladder frame is provided with a first ladder frame,

a second stile, the first and second stiles each having a plurality of posts disposed along axes of the plurality of posts, an

A plurality of rungs extending between the first stile and the second stile, each rung connected to a leg of the plurality of legs of the first stile and a leg of the plurality of legs of the second stile; and

a pair of hinge mechanisms hingedly connecting the first ladder portion to the second ladder portion about a hinge axis, each hinge mechanism adapted to lock the first and second ladder portions such that the first ladder portion and the second ladder portion form an angle therebetween, each hinge mechanism comprising,

a first hinge member operatively connected to the first ladder portion including a plurality of slots peripherally positioned on the first hinge member, the plurality of slots defining a shift pattern,

a second hinge member operatively connected to the second ladder portion, the first and second hinge members being rotatable relative to each other about the hinge axis,

a displacement mechanism comprising

A coaxial axis parallel to one of the plurality of slots such that the displacement mechanism substantially surrounds an outer periphery of the first hinge member,

each slot corresponds to a respective angular position of a plurality of angular positions of the first ladder portion relative to the second ladder portion, and adjacent slots of the plurality of slots are separated by a distance defined along a perimeter of the first hinge member, an

A selector pin adapted to be displaced in the displacement mode and received by a respective slot of a plurality of slots to lock the second ladder portion in a respective angular position relative to a plurality of angular positions of the first ladder portion.

2. The foldable ladder of claim 1, further comprising a locking plate in the second hinge member, the locking plate comprising a plurality of recesses such that a center of the locking plate coincides with the hinge axis, each recess of the plurality of recesses being separated from another recess of the plurality of recesses by an angle corresponding to the angle between the first and second ladder portions.

3. The foldable ladder of claim 2, wherein the angle between the first and second ladder portions is between 0 and 180 degrees.

4. The foldable ladder of claim 3, wherein the first and second ladder portions are lockable at angles of about 0 degrees, about 30 degrees, and about 180 degrees.

5. The foldable ladder of claim 4, wherein the angle between a first recess of the plurality of recesses and a second recess of the plurality of recesses is about 30 degrees, and the angle between the first recess and a third recess of the plurality of recesses is about 180 degrees.

6. The foldable ladder of claim 2, further comprising a locking pin connected to the selector pin, the locking pin adapted to be received by a respective recess of the plurality of recesses of the locking plate, the locking pin configured to move in a direction along an axis of the locking pin,

wherein the locking pin moves into a respective recess of the plurality of recesses of the locking plate when the selector pin moves into a respective slot of the shift mode, and

the locking pin moves away from a respective recess of the plurality of recesses of the locking plate when the selector pin moves away from a respective slot of the shift mode.

7. The foldable ladder of claim 6, wherein the locking pin is configured to be a locking pin

Fully received by a respective recess of the plurality of recesses of the locking plate to lock the first ladder portion and the second ladder portion in respective angular positions;

retracting completely from respective ones of the plurality of recesses of the locking plate to release the first and second ladder sections from respective angular positions; and

abutting against an edge of the second hinge member when the first and second ladder portions are angled at any angle other than a plurality of predetermined angles.

8. The foldable ladder of claim 1, further comprising a selection collar in sliding engagement with the first hinge member, the selection collar engaged with the selector pin and adapted to slide against the first hinge member along a collar axis.

9. The foldable ladder of claim 8, wherein the selector collar is adapted to rotate about the collar axis to move the selector pin along a displacement pattern defined on the first hinge member.

10. The foldable ladder of claim 1, further comprising one or more safety indicators adapted to provide a first indication when the first and second ladder portions are locked in respective angular positions of the plurality of angular positions and a second indication when the first and second ladder portions are unlocked.

11. The foldable ladder of claim 1, wherein each rung includes a flat first surface and a second surface opposite the flat first surface, wherein the flat first surfaces of the first and second ladder portions define a flat standing surface when the first and second ladder portions form an angle of about 180 degrees.

12. The foldable ladder of claim 11, wherein at least a portion of the first surfaces of the first and second ladder portions form an angle relative to a horizontal plane.

13. The foldable ladder of claim 12, wherein, when the angle between the first ladder portion and the second ladder portion is less than 90 degrees, the angled portion of the first surface of the rungs of the first ladder portion defines a flat upper surface and the angled portion of the first surface of the rungs of the second ladder portion defines a flat lower surface such that the flat lower surface of the second ladder portion faces in an opposite direction from the flat upper surface of the rungs of the first ladder portion.

14. The foldable ladder of claim 13, wherein the angled portion of the first surface of the rungs of the second ladder portion faces in the same direction as the first surface of the rungs of the first ladder portion when the angle between the first and second ladder portions is about 180 degrees, such that the angled portions of the first surfaces of the first and second ladder portions both define a flat standing surface.

15. The foldable ladder of claim 14, wherein when the angle between the first ladder portion and the second ladder portion is less than 90 degrees, no angled portion is defined on a second surface of the rungs of the second ladder portion, thereby preventing a user from stepping on the second surface.

16. The foldable ladder of claim 1, wherein the plurality of posts are disposed in a nested arrangement for relative axial movement in a telescoping fashion such that the ladder is extendable or retractable along the axis of the plurality of posts.

17. The foldable ladder of claim 16, wherein each rung is connected to a post of the plurality of posts by a connector assembly having a latch assembly including a release button slidable along a front surface of the rung to unlock or selectively lock the relative axial movement between two adjacent posts of the plurality of posts, the front surface of the rung being substantially perpendicular to a plane orthogonal to the axes of the plurality of posts.

18. A foldable ladder, comprising:

a first ladder section;

The first ladder frame is provided with a first ladder frame,

A plurality of rungs extending between the first stile and the second stile, each rung connected to one of a plurality of legs of the first stile and one of a plurality of legs of the second stile; and

a first hinge member operatively connected to the first ladder portion,

a displacement mechanism comprising a plurality of slots,

a selector pin adapted to be received by a respective slot of a plurality of slots to lock the second ladder portion in a respective angular position relative to the first ladder portion,

a locking plate connected to the second hinge member, the locking plate including a plurality of recesses, an

A locking pin connected to the selector pin, the locking pin adapted to be received by a respective one of the plurality of recesses of the locking plate, the locking pin configured to move in a direction along an axis of the locking pin, the locking pin moving into the respective one of the plurality of recesses of the locking plate when the selector pin moves into the respective one of the plurality of slots of the displacement mechanism, the locking pin moving away from the respective one of the plurality of recesses of the locking plate when the selector pin moves away from the respective one of the plurality of slots of the displacement mechanism.

19. The foldable ladder of claim 18, wherein the locking pin is configured as a locking pin

Fully received by a respective recess of the plurality of recesses of the locking plate to lock the first ladder section and the second ladder section in respective positions;

fully retracting from respective recesses of the plurality of recesses of the locking plate to release the first ladder section and the second ladder section from respective angular positions; and

abutting against an edge of the second hinge member when the first ladder portion and the second ladder portion are angled at any angle other than a plurality of predetermined angles.

20. A foldable ladder, comprising:

a first ladder section;

The first ladder frame is provided with a first ladder frame,

a pair of hinge mechanisms hingedly connecting the first ladder section to the second ladder section about a hinge axis such that the first ladder section and the second ladder section are rotatable about the hinge axis, each hinge mechanism adapted to lock the first and second ladder sections such that the first ladder section and the second ladder section form an angle therebetween, each hinge mechanism comprising,

a first hinge member operatively connected to the first ladder portion,

a locking pin that is elongated and has a non-circular cross-section at its distal end,

the locking pin having a central axis passing through a tip having a non-circular cross-section, the central axis of the locking pin being misaligned with the hinge axis,

the locking pin being mounted on the first hinge part for movement along a central axis of the locking pin radially away from and towards the hinge axis, the locking pin being spring biased radially towards the hinge axis,

the locking pin is rotatable about a central axis of the locking pin by a ladder angle selector, the ladder angle selector permitting manual selection of a desired angle between the first and second ladder portions,

a plurality of recesses each leading radially inward from the end of the second hinge member toward the hinge axis,

the plurality of recesses being angularly spaced about the hinge axis, the angular position of the hinge axis about each recess corresponding to a predetermined angle between the first and second ladder sections,

each recess having a corresponding ladder angle opening defined on the end of the second hinge member,

each ladder angle opening having an opening shape configured to allow insertion of the locking pin therethrough when the locking pin is rotated about a central axis of the locking pin to a rotation in which an orientation of the locking pin cross-section substantially matches the opening shape,

the opening shape is configured to block insertion of the locking pin therethrough when the locking pin is rotated about a central axis of the locking pin to a rotation in which an orientation of the locking pin cross-section does not substantially match the opening shape.

21. The foldable ladder of claim 20, wherein the first ladder portion and the second ladder portion are rotatable relative to each other about the hinge axis, the rotation of the first and second ladder portions relative to each other adapted to position the locking pin proximate to a respective ladder angle opening.

22. The foldable ladder of claim 20, wherein the plurality of rungs comprises a first rung connected to a column of the plurality of columns of the first stile by a first connector assembly, the first rung connected to a column of the plurality of columns of the second stile by a second connector assembly, the first connector assembly and the second connector assembly each having a first release button and a second release button, the first release button slidable along a first surface of the first rung, the second release button slidable along a second surface of the first rung,

the first release button and/or the second release button permit unlocking or selectively locking relative axial movement between two adjacent posts of the plurality of posts.

23. The foldable ladder of claim 22, wherein the first and second release buttons are coupled to a rung pin and a spring, the spring applying a biasing force against the rung pin to engage the rung pin with two adjacent posts of the plurality of posts to selectively lock relative axial movement between the two adjacent posts, the sliding motion of either of the first and second release buttons along the respective front or rear surface retracting the rung pin to unlock the two adjacent posts and thereby permit relative axial movement therebetween.

24. The foldable ladder of claim 23, wherein sliding of one of the first release button or the second release button causes the other of the first release button or the second release button to slide through a frictional engagement between the first release button, the second release button, and the rung pin.

25. The foldable ladder of claim 24, wherein the rung pin comprises a pair of holes, the first release button and the second release button each comprising a handle, each handle insertable into one of the holes in the pair of holes.

26. The foldable ladder of claim 22, the first surface and the second surface each being substantially perpendicular to a flat standing surface of the first rung.

27. The foldable ladder of claim 26, wherein the flat standing surface is a top surface of the first rung if the first rung is located in the first ladder portion.

28. The foldable ladder of claim 27, wherein, if the first rung is located in the second ladder portion, the flat standing surface is a bottom surface of the first rung when an angle between the first ladder portion and the second ladder portion is less than 90 degrees, and

the planar standing surface is a top surface of a first rung of the second ladder portion when an angle between the first ladder portion and the second ladder portion is about 180 degrees.

29. The foldable ladder of claim 22, wherein one or more rungs of the first ladder portion and/or the second ladder portion comprise an angled portion forming an angle between 5 degrees and 45 degrees with respect to a horizontal surface, the angled portion being substantially horizontal as the ladder is rotated toward a vertical wall.

30. The foldable ladder of claim 20, wherein a central axis of the locking pin is non-parallel to the hinge axis.

31. The foldable ladder of claim 20, wherein a central axis of the locking pin is substantially perpendicular to the hinge axis.

32. The foldable ladder of claim 20, wherein a central axis of the locking pin passes through one of the plurality of recesses that receives the locking pin when the locking pin is rotated about the central axis of the locking pin to a position wherein an orientation of the locking pin cross-section substantially matches the opening shape.

33. A foldable ladder, comprising:

a first ladder section;

The first ladder frame is provided with a first ladder frame,

a first hinge member operatively connected to the first ladder portion,

a second hinge member operatively connected to the second ladder portion, the first and second hinge members being rotatable relative to each other about the hinge axis, the second hinge member having an end,

a locking pin that is elongated and has a non-circular cross-section at its distal end, the non-circular cross-section having a first edge and a second edge,

the locking pin having a central axis passing through a tip having a non-circular cross-section, the central axis of the locking pin being non-coaxial with the hinge axis,

the locking pin being rotatable about a central axis of the locking pin by a ladder angle selector, the ladder angle selector allowing manual selection of a desired angle between the first and second ladder sections,

each recess has a corresponding ladder angle opening defined on the end of the second hinge member, each ladder angle opening having an opening shape that allows the locking pin to be inserted therethrough when the locking pin is rotated about a central axis of the locking pin into a position in which a first edge and a second edge of the locking pin are in line with the corresponding ladder angle opening.

34. The foldable ladder of claim 33, wherein a tip of the locking pin has a rectangular cross-section.

35. The foldable ladder of claim 34, wherein the first edge is shorter in length than the second edge.

36. The foldable ladder of claim 33, wherein a central axis of the locking pin is non-parallel to the hinge axis.

37. The foldable ladder of claim 33, wherein a central axis of the locking pin is substantially perpendicular to the hinge axis.

38. The foldable ladder of claim 33, wherein a central axis of the locking pin passes through one of the plurality of recesses that receives the locking pin when the locking pin is rotated about the central axis of the locking pin to a position wherein an orientation of the locking pin cross-section substantially matches the opening shape.