CN106555548B

CN106555548B - Telescopic ladder with retaining mechanism

Info

Publication number: CN106555548B
Application number: CN201610851812.6A
Authority: CN
Inventors: 南森·L·施吕特; 米切尔·I·基弗
Original assignee: Core Distribution Inc
Current assignee: Core Distribution Inc
Priority date: 2015-09-25
Filing date: 2016-09-26
Publication date: 2020-04-21
Anticipated expiration: 2036-09-26
Also published as: CN106555548A; EP3147447A1; EP3147447B1

Abstract

The present application relates to a telescopic ladder with a retention mechanism. A telescoping ladder has a plurality of posts in a nested telescoping arrangement. The telescopic ladder further includes a plurality of post retention mechanisms, each post retention mechanism disposed on an outer surface of a post, each post retention mechanism adapted to retain an immediately adjacent inner post nested within an outer post in a collapsed position, the post retention mechanism of each post preventing posts other than the immediately adjacent inner post nested within the outer post from being extended from its nested arrangement until nested within the outer post and positioned higher than the immediately adjacent inner post of the outer post is fully extended from its nested position. The telescoping ladder disclosed in the present application may allow a user to extend each subsequent nested column in a sequential manner such that the column in the lower portion extends first before the column in the upper portion of the ladder. The telescopic ladder disclosed in the present application may provide an improvement in stability.

Description

Telescopic ladder with retaining mechanism

Technical Field

The present disclosure relates to a telescopic ladder having a retention mechanism.

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 to extend the ladder, or may be folded together for retraction of the ladder.

Disclosure of Invention

In general, the present disclosure relates to the following embodiments:

in a first embodiment, there is provided a telescopic ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

a plurality of posts arranged in a nested arrangement for relative axial movement in a telescoping manner along axes of the plurality of posts between a fully extended position and a collapsed position, wherein each post has a hollow body such that when the ladder is collapsed from the fully extended position, each post substantially nests in another post;

a plurality of rungs extending between the first mullion and the second mullion, each rung connected to a pillar of the first mullion and a pillar of the second mullion; and

a plurality of post retention mechanisms, each disposed on an outer surface of a post, each post retention mechanism adapted to retain an immediately adjacent inner post nested in an outer post in a folded position, the post retention mechanism of each post preventing posts other than the immediately adjacent inner post nested in the outer post from being extended from its nested arrangement until nested in the outer post and positioned higher than the immediately adjacent inner post of the outer post fully extends from its nested position.

In a second embodiment:

each retaining mechanism includes a retaining hammer positioned on an outer surface of each column near a bottom edge of the column, the retaining hammer being flexible between a retaining position and a release position, wherein in the release position the retaining hammer flexes radially outward from the longitudinal axis of the telescopic ladder allowing an immediately adjacent inner column positioned in the outer column to be released from the outer column, and in the retaining position the retaining hammer flexes radially inward toward the longitudinal axis of the telescopic ladder allowing an immediately adjacent inner column of each column to be locked in its nested arrangement in the outer column.

In a third embodiment:

each retention mechanism includes a retention strip positioned on an outer surface of each post such that when folded into a nested arrangement, the retention hammer of an outer post presses against the retention strip of an immediately adjacent inner post at a retention position to lock the outer post together with its immediately adjacent inner post nested in the outer post.

In a fourth embodiment:

the retaining mechanism prevents relative sliding movement between the outer post and the immediately adjacent inner post at the retaining position.

In a fifth embodiment:

each post includes a retention slot through which a retention hammer extends in a retention position, the retention slot being defined along an outer surface of each post.

In the sixth embodiment:

the retention slot of each post is positioned at a longitudinal distance from the upper edge of the post, the longitudinal distance of the retention slot of the outer post corresponding to the axial position of the retention strip immediately adjacent the inner post when in the nested arrangement, such that the retention hammer extends through the retention slot to press against the retention strip immediately adjacent the inner post.

In the seventh embodiment:

the longitudinal distance from the upper edge of each respective post is between about two-thirds of the length of the post and about the length of the post.

In the eighth embodiment:

each holding hammer includes one or more locating projections configured for axially aligning the holding hammer on each respective post, each locating projection being receivable by a corresponding hole on the respective post.

In the ninth embodiment:

each holding hammer has a tapered front surface to allow positioning of the holding hammer on the holding slot of the post, and a vertical rear surface to prevent removal of the holding hammer from the holding slot.

There is also provided in a tenth embodiment a telescopic ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

a plurality of posts arranged in a nested arrangement for relative axial movement in a telescoping manner along axes of the plurality of posts between a fully extended position and a folded position, the plurality of posts including a first post, a second post, and a third post, wherein in the folded position the first post substantially nests in the second and third posts and the second post substantially nests in the third post;

a plurality of rungs extending between the first mullion and the second mullion, each rung connected to a pillar of the first mullion and a pillar of the second mullion;

a plurality of connector assemblies, each connector assembly having a latch assembly including a release button slidable along a front surface of the rail to unlatch or selectively lock relative axial movement between two adjacent posts; and

a plurality of retaining hammers disposed on an outer surface of the column, the retaining hammers on the second column retaining the first column at the folded position and the retaining hammers on the third column retaining the second column at the folded position, the retaining hammers on the second column being releasable after the retaining hammers of the third column release the second column and after the second column is fully extended from its nested arrangement in the third column.

In the eleventh embodiment:

each retention hammer contacts a portion of the peripheral surface of the post, the retention hammers being contoured to conform to the shape of each post.

In the twelfth embodiment:

each connector assembly includes a collar that generally surrounds the post and a ledge portion that is receivable by the ledge, the inner surface of the collar of each connector assembly including a recessed portion for receiving the retaining hammer.

In the thirteenth embodiment:

when the second column is fully extended from its nested arrangement within the third column, the retaining hammer of the second column abuts a female portion of a ferrule of the connector assembly that connects the second column to the ledge.

In a fourteenth embodiment:

when the holding hammer of the second column abuts against the recessed portion of the collar, the first column is released from the second column and is able to slide relative to the second column.

In the fifteenth embodiment:

each latch assembly includes a locking pin configured to extend through a hole in a collar of the connection assembly, the locking pin being receivable by corresponding holes on an upper edge of the third post and a lower edge of the second post to lock relative sliding movement between the second and third posts at a fully extended position.

In the sixteenth embodiment:

each retaining hammer is positioned circumferentially opposite a portion of the peripheral surface of the post adjacent the hole in the ferrule through which the locking pin extends.

In the seventeenth embodiment:

each post includes first and second holding hammers each contacting a portion of a peripheral surface of the post.

In the eighteenth embodiment:

each of the first and second holding hammers is positioned at an angle of about 90 ° in a circumferential direction relative to a portion of the peripheral surface of the post adjacent to a hole in the ferrule through which the locking pin extends.

In a nineteenth embodiment, there is provided a telescopic ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

a plurality of posts arranged in a nested arrangement for relative axial movement in a telescoping manner along axes of the plurality of posts between a fully extended position and a collapsed position, the plurality of posts including an outer post and an immediately adjacent inner post nested within the outer post in the collapsed position;

a plurality of retaining hammers disposed on an outer surface of the posts and the retaining hammers of the outer posts retain the immediately adjacent inner posts at the folded position, the retaining hammers of the outer posts preventing the posts other than the immediately adjacent inner posts from being extended from their nested arrangement until the immediately adjacent inner posts nested in the outer posts are fully extended from their nested position; and

a plurality of air dampers positioned in the plurality of posts, the air dampers adapted to reduce the speed of relative axial movement of the plurality of posts when the posts are folded into the folded position, each air damper having a cut-out portion for allowing the posts to fold without the air damper in the immediately inner post abutting against the retaining hammer of the outer post.

In a twentieth embodiment:

each air damper is positioned at or near the bottom edge of the column.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings.

Drawings

FIG. 1A is a perspective view of a telescoping ladder with rungs shown in a collapsed position, according to an embodiment;

FIG. 1B is a perspective view of the telescoping ladder of FIG. 1A with the rungs in the lower portion of the ladder shown in an extended position;

FIG. 1C is a perspective view of the telescoping ladder of FIG. 1A with the rungs of the lower portion of the ladder shown in an extended position;

FIG. 2A is a cross-sectional view of a rung of the telescoping ladder of FIG. 1A;

FIG. 2B is a cross-sectional view of a rung of a telescoping ladder according to another embodiment;

FIG. 3 is an exploded perspective view of the telescoping ladder of FIG. 1A;

FIG. 4 is a front perspective view of a portion of a column of the ladder of FIG. 1;

FIG. 5 is a cross-sectional view of the telescoping ladder shown in the collapsed position with the holding hammers in the holding position;

FIG. 6 is a cross-sectional view of the telescoping ladder shown in the extended position with the holding hammer in the released position;

FIG. 7 is an enlarged perspective view of the telescoping ladder of FIG. 1A with the posts shown in a transparent view to illustrate interior details therein;

FIG. 8 is a front perspective view of a single post of the telescoping ladder of FIG. 1A;

FIG. 9 is a perspective view of a portion of a connector assembly of the telescoping ladder of FIG. 1A; and is

Fig. 10 is a perspective view of a portion of a telescoping ladder with an air damper, under an embodiment.

Detailed Description

FIG. 1A is a perspective view of a telescoping ladder 10 according to one embodiment.

Referring to FIG. 1A, a telescopic ladder 10 includes a first stile 14 and a second stile 16 (e.g., the left and right hand stiles illustrated in FIG. 1A). Each of the first and second mullions has a plurality of posts 18, the plurality of posts 18 being disposed in a nested arrangement for relative axial movement in a telescoping manner along a longitudinal axis 20 of the plurality of posts 18 between an extended position and a collapsed position. For example, in fig. 1B, the upper portion 22 of the ladder 10 is shown in a collapsed position, with the posts 18 nested within one another in a telescoping manner along the longitudinal axes 20 of the posts 18, while the lower portion 23 is shown in an extended position. In fig. 1C, the upper portion 22 of the ladder 10 is shown in an extended position.

As shown in fig. 1A-1C, the ladder 10 includes a plurality of rungs 24 extending between the first stile 14 and the second stile 16. Each rung 24 may be connected to the post 18 of the first mullion 14 and the post 18 of the second mullion 16. As shown in fig. 1A, each rail 24 may be connected to the post 18 by a connector assembly 26, which will be described later. With continued reference to fig. 1A, in some cases, each rung 24 includes a planar first surface 28 and a planar second surface 30 opposite the planar first surface 28. The first surface 28 of each rail 24 defines a flat standing surface 32. Referring to fig. 1C, when the ladder 10 is extended for use and against a wall, a user may step on the flat first surface 28. The planar standing surface 32 may include a tread 34 (shown in fig. 2A) defined thereon to provide friction between the planar standing surface 32 and a contact surface of a user (e.g., a sole of a user's shoe).

As described further below, the rail 24 may be generally hollow to allow the connector assembly 26 to secure the rail 24 to the posts 18 on each of the right and left hand stiles. Additionally, the hollow body of cross piece 24 allows a pair of latch assemblies (not shown) to be received in cross piece 24 to connect cross piece 24 to post 18. The rails 24 may be extruded from aluminum, but other materials and manufacturing methods may be used.

Rungs 24 may have a generally rectangular cross-section or a parallelogram cross-section, such as those described in U.S. patent publication No. 2012/0267197a1, assigned to the assignee of the present application, the contents of which are incorporated herein by reference in their entirety. While the illustrated FIG. 2A shows a generally rectangular rung 24 with the planar first surface 28 of the rung 24 forming an angle of about 90 with respect to the mullion longitudinal axis 20, FIG. 2B illustrates a rung 24 having a parallelogram cross-section with at least a portion 38 of the first surface 28 (and optionally the second surface 30) forming an angle θ with respect to the mullion longitudinal axis 20, and with the front surface 48 (and the rear surface) parallel to the mullion longitudinal axis 20. The angled portion 38 may form an angle of between about 95 ° and 145 ° (e.g., between 95 ° and 110 °) relative to the longitudinal axis 20 of the mullion. Instead of the parallelogram-shaped rungs 24 shown in fig. 2B, the rungs 24 of fig. 1A-1C may have a flat first surface 28 attached to the rungs 24 or an angled portion integrally formed with the flat first surface 28. This embodiment allows at least the angled portion of the first surface 28 of the rung 24 to be horizontal when the ladder 10 is rotated toward a vertical wall (e.g., supported at an angle against the wall), such that at least the portion 38 of the rung 24 may be nearly horizontal during normal use. However, depending on the angle at which the ladder 10 is supported against a vertical wall, the angled portion 38 may or may not exceed the horizontal position.

In some embodiments, the post 18 is made of aluminum. Other materials are contemplated and within the scope of the present invention. The post 18 is illustrated as having a circular cross-section (when viewed along the longitudinal axis 20 of the post 18). However, the post 18 may have a rectangular cross-section, such as those described in U.S. patent publication No. 2012/0267197a1, assigned to the assignee of the present application, the contents of which are incorporated herein by reference in their entirety. Other cross-sections (e.g., square, oval, or polygonal shapes) are also contemplated. The post 18 may be generally hollow to receive another post 18 from above.

As described above and with reference to fig. 3, crosspiece 24 is connected to post 18 by a plurality of connector assemblies 26. The connector assembly 26 may have a latch assembly received in the hollow portion 45 of each rail 24 to unlock or selectively lock relative axial movement between adjacent posts 18. The connector assembly 26 is described in U.S. patent application nos. 8,387,753B2 and 6,883,645, which are assigned to the assignee of the present application, the contents of each of which are incorporated herein by reference in their entirety. Although the connector assembly 26 of the left hand mullion is a mirror image of the connector assembly 26 of the right hand mullion, the connector assemblies 26 may be substantially identical. Each locking assembly has a release button 46, the release button 46 being manually actuatable to unlock the selectively locked relative axial movement between two adjacent posts 18. The release button 46 is integrally formed with the connector assembly 26 and extends out of the slot 27 of the ledge 24. In the embodiment shown in fig. 1A, release button 46 may be slid inward (e.g., by a user's thumb) along a front surface 48 of ledge 24 to unlock its respective latch assembly. Thus, when the release buttons on both the right and left hand sides of the ledge 24 slide inward along the illustrated arrows 50, the adjacent posts 18 are allowed to move axially along the longitudinal axis 20 of the mullion to collapse or extend. Gravity may cause the post 18 and its rung 24 to fold downward to assume a position similar to the rung 24 shown in the folded portion of the ladder 10 shown in fig. 1A.

It will be apparent to those skilled in the art that a telescopic ladder such as that described herein may be folded and extended without any safety hazard during normal use thereof. For example, several countries have safety regulations that prevent a user from extending the posts 18 of the upper section 22 of the ladder 10 until the posts 18 of the lower section 23 are fully extended. This regulation may improve stability and prevent a user from being injured by stepping on a partially extended ladder 10 that may be unstable and tip over when the user steps thereon. Accordingly, some embodiments disclosed herein include a retention mechanism that allows a telescoping ladder to meet this safety regulation.

FIG. 4 shows an enlarged perspective view of the telescoping ladder with 18i shown in a ghost view to illustrate the interior details of the ladder. In fig. 4, portions of the connector assembly are removed to illustrate details of the post retention mechanism 60. As shown in fig. 4, the telescoping ladder 10 may have a plurality of post retention mechanisms 60. Each post 18 retention mechanism may be disposed on the outer surface 62 of the post 18 to retain the immediately adjacent inner post (inner column)18 therein in the collapsed position. When secured in this manner, the post 18 retention mechanism of each post 18 prevents the posts 18 other than the immediately adjacent inner post 18 within the post 18 from being extended from their nested arrangement until the immediately adjacent inner post 18 nested within the post 18 and positioned higher than the post 18 extends substantially from its nested position. For example, in the cross-section illustrated in fig. 5, the first post 18i surrounds the second post 18j and the third post 18 k. Post 18k fully nests in post 18j and post 18j fully nests in post 18 i. In this arrangement, the post retention mechanism of post 18j locks post 18k to prevent post 18k from being extended until the post retention mechanism of post 18i releases post 18j such that post 18j extends completely out of post 18 i. After the post 18 immediately below it is fully extended, each post 18 is extended, at which point the post 18 retention mechanism releases the post 18 above it.

With continued reference to fig. 5, each post 18 retention mechanism includes a retention hammer 70, the retention hammer 70 being positioned on the outer surface 62 of each post 18 proximate the bottom edge of the post 18. The holding hammer 70 may be flexible relative to the post 18 and may be movable between a holding position and a releasing position. Fig. 5 shows the holding hammer 70 in a holding position, in which the holding hammer 70 prevents the post 18 from extending from the post 18 below, whereas fig. 6 shows the hammer in a release position. As shown in fig. 6, in the release position, the retaining hammer 70 is flexed radially outward from the mullion longitudinal axis 20, thereby allowing an immediately adjacent inner post 18 (e.g., post 18k in fig. 5) positioned in each post 18 (e.g., post 18j in fig. 5) to be released therefrom. Referring back to FIG. 5, in the retention position, the retention hammers 70 flex radially inward toward the mullion longitudinal axis 20, allowing each column 18 to be locked in its nested arrangement in the immediate vicinity of the inner column 18.

Referring back to fig. 3 and 4, each retention mechanism includes a retention strip 80 positioned on the outer surface 62 of each post 18 such that when folded into the nested arrangement, the retention hammer 70 of the post 18 retains the retention strip 80 pressing against the immediately adjacent inner post 18 at a retention position to lock the post 18 with the immediately adjacent inner post 18 nested therein. Thus, the retaining hammer 70 and the retaining strap 80 cooperate to prevent sliding movement of the inner post 18 from sliding through an axial position corresponding to the portion of the hammer 70 pressed against the strap 80. When so locked, the retaining mechanism prevents relative sliding movement between two adjacent posts 18 when the retaining hammer 70 locks the posts 18 in the retaining position. The axial position of each retention strip 80 relative to the retention hammer 70 may be such that in the folded position, the retention hammer 70 of the outer post 18j presses against the retention strip 80 of the immediately adjacent inner post 18k nested therein.

The holding hammer 70 may be positioned and oriented in a position such that the holding hammer 70 may press against the holding strip 80. As shown in fig. 7, each post 18 includes a retaining slot 82 defined along the outer surface 62 of the post 18 for the retaining hammer 70 to extend therethrough at the retaining position. In this position, the holding hammer 70 protrudes through the holding slot 82 and abuts the upper edge 83 of the holding strip 80. If a force is exerted on the upper (or inner) post 18a shown in FIG. 7, the contact of the holding hammer 70 against the edge 83 of the holding strip 80 prevents the upper (or inner) post 18a shown in FIG. 7 from being extended out of the post 18 b. Referring back to fig. 5 and 6, each holding hammer 70 has a tapered front surface 84 to allow positioning of the holding hammer 70 on the holding slot 82 of the post 18. Additionally, each holding hammer 70 has a vertical rear surface 86 to prevent the holding hammer 70 from being removed from the holding slot 82. When positioned in this manner, the retention hammer 70 may extend through the retention slot 82 and abut the retention strip 80 of the column 18 nested inside.

Continuing with the above description, and as best shown in fig. 8, the retention slot 82 of each post 18 is positioned at a longitudinal distance 88 from an upper edge 90 of the post 18. When in the nested arrangement, the longitudinal distance 88 of the retention slot 82 corresponds to the axial position of the retention strap 80 proximate the inner post 18 such that the retention hammer 70 extends through the retention slot 82 to press against the retention strap 80 proximate the inner post (not shown in fig. 8). It should be noted that in fig. 8, the retaining strip 80 of the post 18 is located at a longitudinal distance 92 from the upper edge 90 of the post 18, the longitudinal distance 92 corresponding to the axial position of the retaining hammer that externally surrounds the post (not shown in fig. 8). As shown, the longitudinal distance 88 from the upper edge 90 of the post 18 is between about two-thirds of the length of the post 18 and about the length of the post 18. In the illustrated embodiment, for example, the longitudinal distance 88 from the upper edge 90 of the post 18 is about 3/4 of the length of the post 18.

As shown in fig. 7, to facilitate positioning the holding hammers 70 at the appropriate longitudinal distance 88, each holding hammer 70 includes one or more positioning tabs 94 (positioning tabs) for axially aligning the holding hammer 70 on the post 18. Likewise, each post 18 is formed with a corresponding aperture 96 (shown in fig. 4) at the desired longitudinal distance 88 where the holding hammer 70 is to be positioned. Each locating projection is receivable by a corresponding aperture 120 located on the post 18. Although the illustrated embodiment shows a protrusion, other locating means, such as locating sockets (dimples), pins, studs, buttons, etc. may be used.

With continued reference to fig. 7, the holding hammer 70 may be shaped to generally conform to the post 18 to facilitate assembly of the holding hammer 70 on the post 18. For example, if the post 18 has a generally circular shape when viewed along the longitudinal axis 20 of the mullion, the retention hammer 70 may be made to have a generally curved shape such that when the retention boss (or pin, boss, button, etc.) is received by the corresponding aperture 96 (as best shown in fig. 4), the retention hammer 70 substantially contacts and surrounds (e.g., is flush with) a portion of the peripheral surface 118 of the post 18. Accordingly, in the illustrated embodiment, the holding hammer has a shape corresponding to the portion 116 of the orb when viewed along the longitudinal axis 20 of the mullion. In this embodiment, the holding hammer 70 is positioned flush with the outer surface 62 of the post 18 when the locating boss 94 is pressed against a corresponding hole 96 (shown in fig. 4) of the post 18. The vertical rear surface 86 rests on the edge of the retention slot 82 and the tapered front surface 84 protrudes through the retention slot 82 and presses against the retention strap 80. Alternatively, if the post 18 has a generally square, rectangular, or other flat (non-arcuate) shape when viewed along the longitudinal axis 20 of the mullion, the holding hammer 70 may be made to have a generally flat shape such that when positioned on the post 18, the holding hammer 70 generally contacts and surrounds (e.g., is flush with) a portion 116 of the perimeter of the post 18. The retention hammers 70 may be contoured (e.g., by molding) during the manufacturing process to conform to the shape of each post 18. This embodiment allows the holding hammer 70 to rest securely on the post 18 and press against the holding strip 80 to prevent the post 18 other than the immediately adjacent inner post 18 from being extended until the proximate inner post 18 is fully extended from its nested arrangement in the immediately adjacent outer (surrounding) post 18.

In operation, and referring back to FIGS. 1A-1C, the ladder 10 may be extended from its collapsed state by first extending the outermost posts 18 nested within the posts 18z adjacent the surface on which the ladder 10 is positioned, and then progressively extending each proximate inner post 18. In this embodiment, the bottom-most post 18z may be devoid of a retaining strap 80, but have a retaining hammer 70 extending through a retaining slot 82 to press against the retaining strap 80 immediately adjacent the post 18y nested in the post 18 z. This step may be repeated until each successive post 18 is fully extended from its nested arrangement until the topmost post 18a is fully extended. As will be apparent to those skilled in the art, the topmost post 18a may be devoid of a retaining hammer 70 or retaining slot 82, but with a retaining strip 80 pressed against by the retaining hammer 70 immediately adjacent the outer post 18 b.

As used herein, the terms "substantially nested" or "fully nested" mean that a length of a post 18 of at least about 3/4 is nested in a folded position in an immediately adjacent post 18. The connector assembly 26 of each post 18 may be manipulated (e.g., sliding the release button 46 along the front surface 48 of the ledge 24) to unlock the relative axial movement between two adjacent posts 18. For example, as shown in fig. 6, the connector assembly 26j-k connecting the second post 18j and the third post 18k is released to extend the third post 18k out of the second post 18 j. As previously described, the holding hammer 70 of the second post 18j is not releasable until the holding hammer 70 of the first post 18i releases the second post 18j, and the second post 18j extends substantially from its nested arrangement within the first post 18 i. Once the second post 18j is fully extended, its hammer 70 approaches the connector assembly 26 j-k. Accordingly, when the connector assembly 26j-k connecting the second 18j and third 18k posts is released, the holding hammer 70 of the second post 18j moves to its release position, and the third post 18k is now slidable relative to the second post 18 j. As used herein, the term "generally extends" or "fully extends" means an extended position in which a length of a post 18 of at least about 3/4 extends beyond an immediately adjacent post 18, wherein the post 18 nests in the immediately adjacent post 18 in a folded position.

As best shown in fig. 3, the connector assembly 26 includes a ferrule 100 and a ledge portion 102. The hoop 100 generally surrounds the column 18. Referring again to fig. 3,6 and 9, the inner surface 104 of the ferrule 100 of each connector assembly 26 includes a female portion 106 for receiving the holding hammer 70. For example, as described above, when the second post 18j is fully extended from the nested arrangement in the third post 18k, the retaining hammer 70 of the second post 18j abuts the flange 107 of the female portion 106 of the collar 100 of the connector assembly 26j-k connecting the second post 18j to the rail 24. The abutment of the retention hammers 70 against the female portions 106j-k of the ferrules 100j-k of the connector assemblies 26j-k causes the retention hammers 70 to flex radially outward, thereby releasing the next immediately adjacent inner post (e.g., first post 18 i). So that when the holding hammer 70 of the second column 18j abuts the female portion 106 of the collar 100, the first column 181 is released from the second column 18j and slides relative to the second column 18 j. These steps may be repeated continuously until the ladder 10 is fully extended.

As described above, and with reference back to fig. 3, each locking assembly includes a locking pin 108, the locking pin 108 being configured to extend through a hole 120 in the ferrule 100 of the connection assembly. At the level of the upper edge 90 of the post 18 and the lower edge 114 of the outer post 18b surrounding the post 18, the locking pin 108 is received by the corresponding hole 122 to lock the relative sliding movement between the two posts 18. For example, the locking pins 108j-k of the connector assemblies 26j-k are received by the upper edge 90j of the second column 18j and the lower edge 114k of the third column 18k to lock relative sliding movement between the second column 18j and the third column 18k at the fully extended position. In this embodiment and referring back to fig. 4, each holding hammer 70 is circumferentially positioned in place so as not to interfere with the operation of the locking pin 108 and to utilize space for accommodating the holding hammer 70 at other locations of the ferrule 100. For example, in the views shown in fig. 5 and 6, the locking pin projects in a direction perpendicular to the plane of the drawing. In the view shown in fig. 3, the holding hammer 70 may be positioned on a front portion of the post 18 (e.g., the side facing the user when the user actuates the locking pin 108), and/or a rear side of the post 18 (e.g., the side facing away from the user when the user actuates the locking pin 108).

Although the embodiments described herein illustrate a single holding hammer for each post 18, each post 18 may alternatively include a first holding hammer and a second holding hammer. In this embodiment, and referring to fig. 7, each of the first and second holding hammers is positioned flush with and in contact with a portion 116 of a peripheral surface 118 of the post 18. The portion 116 is at 90 deg. relative to the portion of the post that receives the locking pin 108, as described above. Each of the first and second holding hammers is circumferentially positioned at an angle of about 90 ° relative to a portion 116 of the peripheral surface 118 of the post 116 adjacent a hole 120 in the ferrule 100 through which hole 120 the locking pin 108 extends. This embodiment provides advantages such as compactly packaging the holding hammer 70 at a location having space on the hoop 100 and preventing operation of the holding hammer 70 from interfering with extension and retraction of the locking pin 108. Of course, as previously described, the top-most post 18a does not hold the hammer 70 and the bottom-most post 18z does not hold the strap 80.

It will be apparent to those skilled in the art that when the locking pin 108 is retracted to fold the post 18, the holding hammer 70 moves from the release position shown in fig. 6 to the holding position shown in fig. 5. Once the locking pin 108 is retracted, the holding hammers 70 move radially inward and the post 18 may be folded into a nested arrangement. Some of these embodiments may have dampers to reduce the speed at which the posts 18 fold into the nested arrangement.

Referring now to fig. 10, the telescoping ladder 10 includes a plurality of air dampers positioned in the plurality of posts 18 to reduce the speed of relative axial movement of the plurality of posts 18 when the posts 18 are folded into the folded position. The air damper is described in U.S. patent publication No. 2012/0267197a1, assigned to the assignee of the present application, the contents of which are incorporated herein by reference in their entirety. In the illustrated embodiment, the air damper 224 covers the lower edge 114 of the column 18 to restrict air flow through the column 18. The air damper 224 and the post 18 represent other air dampers and posts 18, although the post 18 on the right mullion may be a mirror image of the post 18. The air damper 224 has two pins 226 on its inner surface 104, the two pins 226 being received in corresponding openings 228 on the lower edge 114 of the post 18 to retain the air damper 224 on the post 18. In fig. 10, a single opening 228 is illustrated, but a second opening is generally similar to the illustrated opening 228 and is correspondingly positioned on the circumference of the post 18 to receive one of the pins 226 on the air damper 224. Additionally, the thickness of the air damper 224 is such that its outer surface 227 contacts the inner surface 229 of the adjacent larger post 18. Accordingly, the air damper 224 provides stability to the lower edge 114 of the inner post 18. The inner surface 229 of the outer column 18 supports the lower edge 114 of the inner column 18 via mutual contact with the air damper 224. The air damper 224 may also have a hole (not shown) at the bottom through which restricted air may flow into the bottom of the column 18 attached to the air damper 224. These holes can be used to control the rate of descent of one column 18 into the column 18 below it.

In some cases, the air damper 224 may be rubbed by the holding hammer 70 as the air damper 224 moves from its release position (e.g., radially inward) to the holding position. In some such cases, as shown in fig. 10, each air damper 224 has a cut-out portion 225 for allowing the column 18 to collapse without the air damper 224 contacting the holding hammer 70 immediately adjacent the inner column 18. This embodiment prevents damage to the air damper 224 and allows the ladder 10 to be easily folded.

The embodiments disclosed herein teach one or more advantages. Ladders such as those disclosed herein may allow a user to extend each subsequent nested column 18 in a sequential manner such that the column 18 in the lower portion 23 extends first before the column 18 in the upper portion 22 of the ladder 10. This embodiment provides improved stability and meets various regulations to provide safe and efficient use of the ladder 10.

Various examples have been described. These and other examples are within the scope of the following claims.

Claims

1. A telescoping ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

2. The telescoping ladder of claim 1, wherein:

3. The telescoping ladder of claim 2, wherein:

4. The telescoping ladder of claim 3, wherein:

5. The telescoping ladder of claim 3, wherein:

6. The telescoping ladder of claim 5, wherein:

7. The telescoping ladder of claim 6, wherein:

8. The telescoping ladder of claim 2, wherein:

9. The telescoping ladder of claim 8, wherein:

10. A telescoping ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

11. The telescoping ladder of claim 10, wherein:

12. The telescoping ladder of claim 10, wherein:

13. The telescoping ladder of claim 12, wherein:

14. The telescoping ladder of claim 13, wherein:

15. The telescoping ladder of claim 11, wherein:

16. The telescoping ladder of claim 15, wherein:

17. The telescoping ladder of claim 10, wherein:

18. The telescoping ladder of claim 17, wherein:

19. A telescoping ladder comprising:

a first vertical frame and a second vertical frame,

a second mullion, each of the first and second mullions having:

20. The telescoping ladder of claim 19, wherein:

each air damper is positioned at or near the bottom edge of the column.