The present invention relates generally to ladders and, more particularly, to ladders having components and features to provide selective adjustability as well as methods of making and using such ladders.
Ladders are conventionally utilized to provide a user thereof with improved access to elevated locations that might otherwise be inaccessible. Ladders come in many shapes and sizes, such as straight ladders, extension ladders, stepladders, and combination step and extension ladders. So-called combination ladders (sometimes referred to as articulating ladders) may incorporate, in a single ladder, many of the benefits of multiple ladder designs.
Straight ladders, extension ladders or combination ladders (when configured as straight or an extension ladder), are ladders that are conventionally positioned against an elevated surface, such as a wall or the edge of a roof, to support the ladder at a desired angle. A user then ascends the ladder to obtain access to an elevated area, such as to an upper area of the wall or access to the roof. A pair of feet or pads, one being coupled to the bottom of each side rail, is conventionally used to engage the ground, a floor or some other supporting surface.
Step ladders and combination ladders (when configured as a step ladder) are generally considered to be self-supporting in that they include a first rail assembly which includes steps or rungs that is coupled to a second rail assembly or other support structure. The first and second rail assemblies are typically positioned at an acute angle relative to each other so that there are multiple feet or support members—at least three, but typically four—to support the ladder in a free standing position. Thus, the ladder may be used without the need to lean the ladder against a wall or other vertical support structure.
While the size and configuration of ladders may vary considerably, the rails of such ladders are conventionally spaced apart approximately 16 to 18 inches. In some applications, such as when the ladder is very tall, it may become desirable to have the feet spaced apart a greater distance to provide a widened footprint and improve stability. Such may also be the case regardless of the type of ladder (e.g., extension ladder or step ladder). Additionally, it oftentimes desirable to use a ladder in a location where the ground or other supporting surface is not level. Positioning the ladder on such an uneven support surface, without taking further action, results in the ladder being positioned at an undesirable lateral angle (i.e., so that the rungs or steps are not level) and likely makes use of the ladder unsafe.
There have been various efforts to remedy such issues with conventional ladders. For example, various embodiments of leg levelers—accessories that attach to the bottom portion of a ladder's rails—have been utilized to compensate for uneven surfaces by “extending” the length of the rail. Additionally, various embodiments of ladder stabilizers have been utilized wherein additional structural components are coupled to the ladder rails to alter the “footprint” of the ladder, typically making the footprint wider, in an effort to improve the stability to such ladders.
However, such efforts to provide additional stability to ladders have also had drawbacks. Often, leg levelers and stabilizers are provided as aftermarket items and are attached to the ladder by an end user. Such installation may not always be done with the appropriate care and attention. Additionally, such attachments or accessories are often intended to be removed after use meaning that they may be lacking in their structural integrity in their coupling with the ladder.
There is a continuing desire in the industry to provide improved functionality of ladders while maintaining or improving the safety and stability of such ladders. Thus, it would be advantageous to provide ladders with adjustable components that enable the ladder to be used on a variety of support surfaces while also perhaps providing enhanced stability. It would also be advantageous to provide adjustment mechanisms for ladders that enhance the utility of the ladder. Further, it would be advantageous to provide methods related to the manufacture and use such ladders, components and mechanisms.
In accordance with the present invention, various embodiments of ladders, actuating mechanisms, leveler mechanisms and related methods are provided.
In accordance with one embodiment, a ladder is provided that includes a first rail assembly. The first rail assembly comprises: a pair of inner rails and a pair of outer rails, the pair of inner rails being slidably disposed in a upper portion of pair of outer rails; a first plurality of rungs coupled between the pair of inner rails; and a second plurality of rungs coupled between the pair of outer rails. The ladder additionally includes a pair of leveler mechanisms, each leveler mechanism being associated with one of the pair of outer rails. Each leveler mechanism includes a leg member slidably disposed within a lower portion of its associated outer rail and an actuating mechanism configured to enable longitudinal movement in an a first direction and a second, opposite direction when actuated, but allow movement in only the first direction when not actuated. A spring is configured to maintain a biasing force on the leg member in the second direction.
In one particular embodiment, the actuating mechanism includes a first engagement pin and a second engagement pin, each of the first and second engagement pins being sized and configured to engage openings formed in the leg member.
In one embodiment, the openings include a first column of openings and a second column of openings, wherein the first column of openings is longitudinal offset from the second column of openings.
In one embodiment, each of the openings in the first column of openings and each of the openings in the second column of openings include a substantially planar upper surface and a substantially arcuate lower surface.
In one embodiment, the first and second engagement pins and the first and second columns of openings are arranged such that the first engagement pin is in a disengaged state while the second engagement pin is in an engaged state.
In one embodiment, the ladder may further include a pull ring pivotally coupled with each of the engagement pins.
In one embodiment, each of the engagement pins includes a hole or an elongated slot formed therein and wherein a portion of the pull ring is pivotally and slidably disposed in the hole or elongated slot of each engagement pin.
In one embodiment, the spring includes a first end coupled with one of the outer rails and a second end coupled with the leg member of one of the leveler mechanisms.
In one embodiment, the leveler mechanism further includes a laterally protruding stop member coupled with the leg member.
In accordance with another aspect of the invention, an actuating mechanism is provided. The actuating mechanism includes a body, a first engagement pin at least partially disposed within the body, a second engagement pin at least partially disposed within the body, a first biasing member disposed between the first engagement pin and a portion of the body, a second biasing member disposed between the second engagement pin and another portion of the body, and a pull ring having a first portion pivotally coupled with the first engagement and a second portion pivotally coupled with the second engagement pin.
In one embodiment, the first engagement pin includes a hole or an elongated slot and wherein the first portion of the pull ring is slidably disposed within the hole or elongated slot of the first engagement pin; the second engagement pin includes a hole or an elongated slot and wherein the second portion of the pull ring is slidably disposed within the hole or elongated slot of the second engagement pin.
In one embodiment, each of the engagement pins includes a substantially cylindrical body portion and an angled engagement surface. The angled engagement surface of each of the first and second engagement pins includes a substantially planar surface which may be positioned at an angle of approximately 60° relative to a longitudinal axis extending through the cylindrical body. In one embodiment, the engagement surface of the first engagement pin and the engagement surface of the second engagement pin are substantially coplanar.
In accordance with another aspect of the invention, a method of modifying a ladder is provided. The method includes unlocking a first rail assembly from a second rail assembly, sliding the first rail assembly relative to the second rail assembly until the first assembly is uncoupled from the second rail assembly, providing a third rail assembly, the third rail assembly having a leveler mechanism coupled with a rail, sliding the third rail assembly onto the second rail assembly, and locking the third rail assembly in a desired position relative to the second rail assembly.
In one embodiment, the acts of unlocking, sliding the first rail assembly, sliding the third rail assembly and locking are accomplished by a user without the aid of tools.
In one embodiment, providing a third rail assembly, includes providing a rail assembly having a first leveler mechanism coupled with a first rail and a second leveler mechanism coupled with a second rail.
In accordance with another embodiment of the present invention, an actuating mechanism is provided which comprises a first structure and a second structure slidably disposed adjacent the first structure, the second structure having a plurality of engagement surfaces. The mechanism further includes a body coupled with the first structure and at least two engagement pins slidably displaceable relative to the body, wherein the plurality of engagement surfaces and the at least two engagement pins are arranged such that only a single engagement pin of the at least two engagement pins is in abutting engagement with an engagement surface of the plurality of engagement surfaces at one time. The mechanism additionally includes at least one biasing member configured to bias the at least two engagement pins towards engagement with the engagement surfaces.
In one embodiment, act the plurality of engagement surfaces are arranged in at least two laterally spaced columns. In one particular embodiment, the at least two laterally spaced columns include a first column having a first plurality of engagement surfaces and a second column having a second plurality of engagement surfaces, wherein the first plurality of engagement of surfaces are longitudinally staggered relative to the second plurality of engagement surfaces along a length of the second structure.
In one embodiment, the plurality of engagement surfaces are arranged in a single column.
In one embodiment, the at least two engagement pins include 3 or more engagement pins.
In one embodiment, the engagement pins are each configured as a dog.
In one embodiment, each of the at least two engagement pins includes an angled engagement surface and an abutment surface.
In one embodiment, the engagement pins each include a substantially cylindrical portion.
In one embodiment, the engagement surfaces are configured as a plurality of scallops.
In one embodiment, the engagement surfaces are configured as openings.
Additional features and various advantages of the invention will become apparent upon review of the detailed description and associated drawings. It is noted that features or components of one described embodiment may be combined with features or components or another described embodiment without limitation.
The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
Referring to
The combination ladder 100 also includes a second rail assembly 114 that includes an inner assembly 114A slidably coupled with an outer assembly 114B. The inner assembly 114A includes a pair of rails 116 coupled with a plurality of rungs 118 and is configured similar to the inner assembly 102A of the first rail assembly 102A described hereinabove. Likewise, the outer assembly 114B includes a pair of rails 120 coupled with a plurality of rungs 122 and is configured similar to the outer assembly 102B of the first rail assembly 102 described hereinabove. Locking mechanisms 124 may be associated with inner and outer assemblies 114A and 114B to enable selective positioning of the inner assembly 114A relative to the outer assembly 114B as described hereinabove with respect to the first rail assembly 102.
One exemplary locking mechanism that may be used with the first and second rail assemblies 102 and 114 is described in U.S. Pat. No. 8,186,481, issued May 29, 2012, the disclosure of which is incorporated by reference herein in its entirety. While the locking mechanism described in U.S. Pat. No. 8,186,481 is generally described in conjunction with an embodiment of an adjustable step ladder, such a locking mechanism may by readily used with an embodiment such as the presently described combination ladder as well. It is additionally noted that, in one embodiment, the rail assemblies 102 and 114 may be configured similar to those which are described in U.S. Pat. No. 4,210,224 to Kummerlin, the disclosure of which is incorporated by reference in its entirety. Of course, other configurations of rail assemblies may be utilized.
The first rail assembly 102 and the second rail assembly 114 are coupled to each other may way of a pair hinge mechanisms 126. Each hinge mechanism 126 may include a first hinge component coupled with a rail of the first rail assembly's inner assembly 102A and a second hinge component coupled with a rail of the second rail assembly's inner assembly 114A. The hinge components of a hinge pair 126 rotate about a pivot member such that the first rail assembly 102 and the second rail assembly 114 may pivot relative to each other. Additionally, the hinge mechanisms 126 may be configured to lock their respective hinge components (and, thus, the associated rails to which they are coupled) at desired angles relative to each other. One example of a suitable hinge mechanism is described in U.S. Pat. No. 4,407,045 to Boothe, the disclosure of which is incorporated by reference herein in its entirety. Of course other configurations of hinge mechanisms are also contemplated as will be appreciated by those of ordinary skill in the art.
The combination ladder 100 is constructed so as to assume a variety of states or configurations. For example, using the locking mechanisms (112 or 124) to adjust a rail assembly (102 or 114) enables the ladder 100 to adjust in height. More specifically, considering the first rail assembly 102, as the rail assembly 102 is adjusted—with the outer assembly 102B being displaced relative to the inner assembly 102A—the associated locking mechanisms 112 engages the inner and outer assemblies (102A and 102B) when they are at desired relative positions with the rungs (106 and 110) of the inner and outer assemblies (102A and 102B) at a desired vertical spacing relative to each other. At some of the adjustment heights of the rail assembly 102, at least some of their respective rungs (106 and 110) align with each other (such as shown in
Considering the embodiment shown in
Additionally, the hinge mechanisms 126 provide for additional adjustability of the ladder 100. For example, the hinge pairs 126 enable the first and second rail assemblies 102 and 114 to be adjusted to a variety of angles relative to each other. As shown in
The first rail assembly 102 additionally includes an integrated leveler mechanism 130 associated with each rail 108 of the outer assembly 102B. The leveler mechanisms 130 may be independently actuated to compensate for an uneven support surface (e.g., sloping ground, a step on one side of the ladder, etc.) upon which the first assembly 102 may be positioned. As will be discussed in further detail below, in certain embodiments, the leveler mechanisms 130 may be deployed or extended in a “hands-free” manner and include a “no-catch” release/actuating mechanism to avoid inadvertent release of the leveler mechanism 130 while, for example, a user is standing on the ladder 100.
Referring to
The leveler mechanism 130 may also include an actuating mechanism 140 that, in some embodiments, enables the leg member to be displaced in a generally downward direction (when in the orientation shown in
The leveler mechanism 130 may further include a foot 144 coupled to a lower end of the leg members 132 for engagement with the ground or other supporting surface. The foot 144 may be configured to provide substantial friction or “grip” when engaged with a supporting surface. One example of a foot that may be used the leveler mechanism includes a snap-on foot such as described in U.S. Patent Application Publication No. 2012/0211305 filed on Feb. 22, 2012, the disclosure of which is incorporated by reference herein in its entirety. Other feet may include, for example, spikes or other structure for penetrating the ground such as is used in many extension ladders.
A stop member 146 may be coupled with the leg member 132, the foot 144 or both, and serve to limit the travel of the leg member 132 as it is displaced upwards within the channel of the rail 108 (e.g., by abutting the rail 108 when in the retracted state). Additionally, or alternatively, the stop member 146 may act as an engagement surface for a user to abut with their own foot (or hand, if desired,) so as to displace the leg member 132 downward. While shown as being positioned on the laterally outer portion of the leg member 132, in other embodiments, the stop member 146 may be positioned on a laterally inner portion of the leg member 132 or on a front or rear facing portion of the leg member 132. Additionally, while only one stop member 146 is shown, multiple stop members may be coupled with (or formed as an integral part of) the leg member 132 to provide convenient access to a user regardless of where they are standing.
Referring to
Rather, the uppermost opening 150 of the second column 152B is positioned at a location that is longitudinally between the uppermost and second uppermost openings 150 of the first column 152A. The remaining openings 150 follow a similar arrangement or pattern. It is noted that, in other embodiments, a different number of columns (e.g., one, three, etc.) may be used if desired. Additionally, in other embodiments, the columns of openings 150 may not necessarily be offset from one another. In some embodiments, a first column of openings may be longitudinally aligned with another column of openings, while remaining staggered (longitudinally unaligned) with yet other columns.
In the embodiment shown in
The leg member 132 is sized and configured to be slidably disposed within the channel defined by the rail 108 of the outer assembly 102B. The leg member 132 may be various lengths, and have a various number of openings 150 formed therein depending, for example, on the amount of adjustment that is desired to be obtained from the leveler mechanism 130. In one particular embodiment, the leg may be configured to provide up to approximately 8½ inches of adjustment on each side of the outer assembly 102B. Of course, the leveler mechanism 130 may be configured to provide more or less adjustability if desired and depending, for example, on the size of the ladder or the type of ladder (e.g., combination, extension, step, etc.). The leg 132 may further include additional openings, abutments or features for integration or coupling with other components. For example, openings or slots may be formed for coupling with the foot 144 or the stop member 146 or with other components described herein. In one embodiment, the leg 132 may be formed of a material comprising aluminum or an aluminum alloy. Aluminum provides a relatively high strength to weight ratio that may be desirable in such a component. However, other materials may be used as will be appreciated by those of ordinary skill in the art.
Referring to
Referring to
It is noted that in
Referring more particularly to
While a specific actuating mechanism has been shown and described, it is noted that other mechanisms may be employed if desired. For example, a mechanism similar to the locking mechanisms 112 and 124 may be used if desired or other embodiments, such as described below, may be used. Additionally, other components may be used in the mechanism. For example, a lever or cammed mechanism may be used in place of the pull ring if desired. However, it is noted that use of the pull ring requires affirmative action (rotating and outward displacement) to effect actuation and helps to prevent inadvertent actuation such as by a falling tool or from a bump by user's foot or leg. Further, while described as being positioned on the laterally outer portion of the rail 108, the actuating mechanism (including the body 182, pull ring 142, etc.) may be positioned at a laterally inward location of the rail 108 and leg member 132 or at some other location if desired. Placing the actuating mechanism 140 “inside” the rail 108 or at some other location may provide additional protection from an inadvertent displacement of the engagement pins 162.
Referring now to
The spring member 190 is configured to automatically retract (or at least assist in the retraction of) the leg member 132 from an extended position (e.g.,
Another stop member 192 may be coupled to the rail 108 and act to limit the upward travel of the leg member 132 when the spring member 190 pulls on the leg member 132 to position it in a retracted state. In one embodiment, the stop member 192 may be formed of a material such as plastic or rubber, although it may be formed of other materials including metals and metal alloys. When the leg member 132 is in a retracted position (e.g.,
Referring to
The engagement pins 204 are positioned within a body 210 and are biased toward the rail 108 and leg member 132 by way of associated springs 212 or other biasing members. In the embodiment shown, there are four engagement pins 204 vertically aligned with respect to each other. The engagement pins 204 each extend through an associated opening in the rail 108 of the outer assembly 102B and are configured to alternately engage one of the plurality of openings 150 formed in the leg member 132. For example, as shown in
As seen in
Referring to
In one embodiment, the openings 150 may be sized such that only a portion of an engagement pin may extend therethrough. For example, in one embodiment, each of the pins 202 may exhibit a height of approximately 7/16 of an inch, wherein the openings 150 may each exhibit an overall height of approximately ¼ of an inch. Additionally, in one particular embodiment, the pins 202 may be spaced approximately ⅞ of an inch (center to center) while the openings are spaced approximately ½ of an inch (center to center). Such an arrangement results in an adjustment increment of approximately ⅛ of an inch. In other words, every time the leg member 132 moves downward relative to the rail 108 a distance of ⅛ of an inch, a new engagement pin 202 engages an opening such as described with respect to the sequence depicted in
The embodiments of the leveler mechanism 130 described above provide a variety of advantages. For example, the leveler mechanism is integrated with the ladder and is substantially “self-contained” meaning that it is not an add-on feature or structure that is often cumbersome, awkward and clumsy. Rather, the leveler mechanism is simply an integral part of the ladder. In many add-on style levelers found in the prior art, the position and attachment of such levelers often renders the ladder more susceptible to bumps and inadvertent abuse because the levelers add to the size and bulk of the ladder (typically in a lateral direction from the rails). Such bumps and abuse often result in the bending of the rails such that they “toe-in” and render the ladder less stable.
Additionally, the leveler mechanism of the present invention provides a method of modifying a ladder that is simple and may be accomplished without tools. For example, the outer assembly of an existing ladder that does not include a leveler mechanism may simply be removed from the inner assembly (i.e., by releasing associated locks and sliding the outer assembly off of the inner assembly) and then replaced by positioning a new outer assembly that does include a leveler mechanism (e.g., similar to outer assembly 102B) on the inner assembly and locking it in place with the locks (e.g., 112). Thus, a user needs no tools, but only needs to activate the locks on an existing ladder, remove the existing outer assembly, replace it with a new outer assembly containing the leveler mechanisms, and lock the new outer assembly in place. These actions are similar to the regular operation of the ladder when extending it to a new height. Users will be familiar with this operation and the integrity of the ladder won't be compromised by, for example, drilling attachment holes into existing components or installing new fasteners. In another example, a user could replace the base of an extension ladder or an adjustable step ladder in a similar manner to provide a new base with integrated leveler mechanisms.
It is also noted that when the leg members of the present invention are positioned within rails that are angled or flared outwardly relative to each other, the extension of the leg member provides a widened base when in an extended state, adding to the stability of the ladder, without the need to pivot or articulate the leg member as is typically done with many prior art stabilizers.
While the leveler mechanisms have been described in association with a single rail assembly, it is noted that leveler mechanisms may be associated with either rail assembly, or with both rail assemblies (e.g., 102 and 114) if desired. Additionally, while described using an example of a combination ladder, levelers such as described herein may be used with a variety of ladders including extension ladders and step ladders including, but not limited to, the various ladders described in the patents incorporated by reference herein.
Further, a similar adjustment mechanism may be used to connect any two components of a ladder. Thus, for example, the actuation mechanism and the associated openings described with regard to the leveler mechanism could be used in adjusting the inner and outer assemblies of a ladder. In another embodiment, such an arrangement could be used in coupling a safety rail or other accessory or component to a ladder. In another embodiment, such an arrangement may be used in coupling two different components of a ladder in a man hole.
In another example, a stabilizer (sometimes referred to as an outrigger) may be configured to include the actuating mechanisms or other components described herein. For example, referring to
The ladder 300 also includes stabilizers 320. In one embodiment, a stabilizer 320 may be associated with each of the side rails 308 including an adjustable leg member 322 that is pivotally coupled to side rail 308 such as by way of an associated bracket 324. The leg member 322 may be pivotally positioned between at least two positions (e.g., a stored position, and an extended position) as indicated by directional arrow 326 and by dashed lines. The leg member 322 may be configured to be pivoted generally in a common plane defined by the two side rails 308, or it may be configured to be pivoted out of plane relative to the side rails 308. In one embodiment, the adjustable leg may be pivotable about multiple axes.
The adjustable leg member 322 may include, for example, two (or more) leg components 322A and 322B that are telescopically coupled to one another (e.g., one being inserted within an internal space defined by the other, the two components being slidably displaceable relative to each other as indicated by directional arrow 328) and a foot member 323 coupled to an end of the second leg component 322B. An adjustment mechanism 330 may be associated with the two leg components 322A and 322B to control the adjustment of the leg member 322. For example, the adjustment mechanism described with respect to
Referring to
Referring to
The adjustment mechanism 370 further includes a plurality of engagement pins generally identified by 376 (with specific pins identified as 376A-376C in certain drawings) having a first portion 378 (
The pins 376 are configured to be displaced such that they can slide into and out of engagement with a scallop 374 when aligned therewith. Biasing members 380 (e.g., springs or other appropriate structures or devices) are associated with each of the engagement pins 376 to bias the pins towards engagement with a scallop 374. The pins 376 and biasing members 380 (
The adjustment mechanism 370 further includes an actuator, such as a handle 384, configured to displace all of the pins 376 out of engagement with the scallops 374 such that the body 382, pins 376 and related components may be slidably displaced along the rail 354 (an relative to the first component 372). When the handle is released, the forces applied by the biasing members 380 cause one of the pins 376 to slide into engagement with a scallop 374 when it becomes aligned as the body 382 (along with the pins 376 and associated components) are slidably displaced relative to the first component and its plurality of scallops 374.
For example, referring to
In one embodiment, the scallops 374 may be spaced from each other along a longitudinal axis at a distance of approximately 0.6 inch (center to center) and exhibit a “depth” from the top surface of the first component 372 to the lowest point of the concave scallop of approximately 0.13 inch. The pins 376A-376C may be spaced, for example, approximately 0.8 inch from each other (center to center). Using such spacing, the body 182 (and associated components) may be adjusted relative to the rail 354 and associated first component in increments of approximately 0.2 inch. Of course, in other embodiments, such sizes and relationships may be changed for greater or smaller increments of adjustment.
As shown in
When the handle 382 is released, the biasing members 380 press the pins 376 against the surface of the aligned scallops 374 until one of the pins is aligned with a scallop and it engages therewith. For example, as shown in
In one embodiment, the ends 388 of the pins 376 (
As seen in
Additionally, it is noted that a cover may be disposed about, for example, the body 382, engagement pins 376 and various other components. The cover may keep dirt and debris from entering into the mechanism 370 which might otherwise damage components or degrade the operability of the mechanism. It may also keep a user's fingers or clothes from getting caught or pinched within the device (e.g., by the pins 376 when sliding between engaged and disengaged positions).
While described in association with a stabilizer for an extension ladder, it is noted that the adjustment mechanism described with respect to
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, any features or components of a given embodiment may be combined, without limitation, with features or components of any other described embodiment. Additionally, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
The present application is a continuation of U.S. patent application Ser. No. 18/356,079 entitled ADJUSTABLE LADDERS, LADDER COMPONENTS AND RELATED METHODS, filed 20 Jul. 2023, which is a continuation of U.S. patent application Ser. No. 16/356,833 entitled ADJUSTABLE LADDERS, LADDER COMPONENTS AND RELATED METHODS, filed 18 Mar. 2019, now U.S. Pat. No. 11,746,596, which is a continuation of U.S. patent application Ser. No. 15/791,091 entitled ADJUSTABLE LADDERS, LADDER COMPONENTS AND RELATED METHODS, filed 23 Oct. 2017, now U.S. Pat. No. 10,233,693, which is a continuation of U.S. patent application Ser. No. 14/479,035 entitled ADJUSTABLE LADDERS. LADDER COMPONENTS AND RELATED MATTERS, filed 5 Sep. 2014, now U.S. Pat. No. 9,797,194, which claims the benefit of U.S. Provisional Patent Application No. 61/674,882, filed 24 Jul. 2012, entitled ADJUSTABLE LADDERS, LADDER COMPONENTS AND RELATED METHODS, and U.S. Provisional Patent Application No. 61/883,650, filed 27 Sep. 2013, entitled STEP LADDERS, the disclosures of which are incorporated by reference herein in their entireties.
Number | Date | Country | |
---|---|---|---|
61883650 | Sep 2013 | US | |
61674882 | Jul 2012 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 18356079 | Jul 2023 | US |
Child | 18584724 | US | |
Parent | 16356833 | Mar 2019 | US |
Child | 18356079 | US | |
Parent | 15791091 | Oct 2017 | US |
Child | 16356833 | US | |
Parent | 14479035 | Sep 2014 | US |
Child | 15791091 | US |