Adjustable ladders and related components

Adjustable ladders may include a pair of side rails having a plurality of rungs extending therebetween, and a pair of adjustable legs associated with the side rails. A pair of swing arms may include a first end pivotally coupled with a side rail, or a bracket associated with the side rail, as well as a second end pivotally coupled with an adjustable leg. The swing arm may be configured as a nonlinear structure. In one embodiment, the swing arm may include a first section that extends from a second section at a defined angle. The first and second sections may exhibit different lengths. Adjustment mechanisms may be pivotally coupled with an upper end of the adjustable legs. In one embodiment, the adjustment mechanisms may be configured such that, when actuated, they may be displaced in one direction while resisting displacement in a second, opposite direction.

TECHNICAL FIELD

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.

BACKGROUND

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 in an “extension” state or condition), 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 is 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 ascending 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 a ladder to be used on a variety of support surfaces while also perhaps providing enhanced stability. It would also be advantageous to provide methods related to the manufacture and use such ladders.

BRIEF SUMMARY OF THE INVENTION

In accordance with certain aspects of the invention, adjustable ladders and related components. In one particular aspect, a ladder is provided that includes a pair of spaced apart rails and a plurality of rungs extending between and coupled to the pair of spaced apart rails. The ladder additionally includes pair of adjustable legs, each adjustable leg slidably being coupled with one of the pair of spaced apart rails. A pair of brackets are configured such that each bracket is coupled to one of the pair of spaced apart rails. The ladder further includes a pair of swing arms, each swing arm having a first end pivotally coupled to one of the pair of brackets and a second end pivotally coupled with one of the pair of adjustable legs, wherein each swing arm exhibits a nonlinear geometry between its first end and its second end.

In accordance with one embodiment, each swing arm includes a first section and a second section, the first end extending from the second section at a defined angle less than 180°.

In accordance with one embodiment, the first section includes the first end, the second section includes the second end, and wherein the first section exhibits a first length and the second section exhibits a second length that is greater than the first length.

In accordance with one embodiment, a ratio of the second length to the first length is at least approximately 2:1.

In accordance with one embodiment, the defined angle is approximately 100° to approximately 140°.

In one embodiment, a location of the pivotal coupling of each swing arm and its associated bracket is positioned laterally between the pair of spaced apart rails. Additionally, the location of the pivotal coupling of each swing arm and its associated bracket may be positioned below a lowermost rung of the plurality of rungs.

In accordance with one embodiment, the ladder may further include a pair of adjustment mechanisms. Each adjustment mechanism may include a bar coupled with an associated rail of the pair of spaced apart rails, a body slidingly coupled with the bar, and an actuating mechanism. The actuating mechanism is configured to selectively enable sliding displacement of the body in a first direction while prohibiting sliding displacement in a second direction, the second direction being opposite of the first direction, and also selectively enable sliding displacement of the body in the second direction while prohibiting sliding displacement in the first direction. Each of the pair of adjustable legs includes a first end pivotally coupled with the body of an associated one of the pair of adjustment mechanisms.

In accordance with one embodiment, the ladder further includes a pair of feet, each foot being coupled to a second end of one of the pair of adjustable legs.

In accordance with one embodiment, the actuating mechanism includes a first set of engagement plates and a first biasing member located and configured to bias the first set of engagement plates substantially in the first direction into engagement with the bar.

In accordance with one embodiment, the actuating mechanism includes a second set of engagement plates and a second biasing member located and configured to bias the second set of engagement plates substantially in the second direction into engagement with the bar.

In one embodiment, the actuating mechanism includes an actuating structure configured to selectively displace at least one of the first set of engagement plates and the second set of engagement plates such that they are disengaged from the bar. The actuating structure may further be configured to selectively displace both the first set of engagement plates and the second set of engagement plates such that they are disengaged from the bar at the same time.

In accordance with one embodiment, the bar includes a longitudinal edge having a plurality of engagement features formed thereon.

In one embodiment, the ladder further comprises a second pair of spaced apart rails and a second plurality of rungs extending between and coupled to the second pair of spaced apart rails.

In accordance with another aspect of the invention, a ladder is provided that includes a pair of spaced apart rails, a plurality of rungs extending between and coupled to the pair of spaced apart rails and a pair of adjustment mechanisms. Each adjustment mechanism includes a bar coupled with an associated rail of the pair of spaced apart rails, a body slidingly coupled with the bar, and an actuating mechanism. The actuating mechanism is configured to selectively enable sliding displacement of the body in a first direction while prohibiting sliding displacement in a second direction, the second direction being opposite of the first direction, and also selectively enable sliding displacement of the body in the second direction while prohibiting sliding displacement in the first direction. The ladder also includes a pair of adjustable legs, each leg having a first end pivotally coupled with the body of an associated one of the pair of adjustment mechanisms.

In accordance with one embodiment, the actuating mechanism includes a first set of engagement plates and a first biasing member located and configured to bias the first set of engagement plates substantially in the first direction into engagement with the bar.

In accordance with one embodiment, the actuating mechanism includes a second set of engagement plates and a second biasing member located and configured to bias the second set of engagement plates substantially in the second direction into engagement with the bar.

In accordance with one embodiment, the actuating mechanism includes an actuating structure configured to selectively displace at least one of the first set of engagement plates and the second set of engagement plates such that they are disengaged from the bar. In one embodiment, the actuating structure is configured to selectively displace both the first set of engagement plates and the second set of engagement plates such that they are disengaged from the bar at the same time.

Features of any of the embodiments described herein may be combined with features of other embodiments without limitation.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Referring toFIGS. 1 and 2, a ladder100is shown in accordance with an embodiment of the present invention. The ladder100includes a first assembly102having a pair of spaced apart rails104and a plurality of rungs106extending between, and coupled to, the rails104. The rungs106are substantially evenly spaced, substantially parallel to one another, and are configured to be substantially level when the ladder100is in an orientation of intended use, so that they may be used as “steps” for a user to ascend the ladder100as will be appreciated by those of ordinary skill in the art.

The ladder100shown inFIGS. 1 and 2is configured as an extension ladder and also includes a second assembly108(see, e.g.,FIG. 1) having a pair of spaced apart rails110and a plurality of rungs112extending between, and coupled to, the rails110. The first assembly102and the second assembly108may be slidably coupled to one another such that the second assembly108may be selectively displaced relative to the first assembly102to effectively alter the height of the ladder100. An extension adjustment mechanism114may be coupled with the second assembly108and interact with the first assembly102to enable the selective displacement between the two assemblies102and108and thereby alter the height of the ladder100. The relationship and interaction of the first assembly102, the second assembly108and the extension adjustment mechanism114in an extension ladder are known by those of ordinary skill in the art and need not be described in further detail herein. It is also noted that, while the embodiment described herein is shown and described as an extension ladder, the present invention embraces additional embodiments including, for example, straight ladders, step ladders and combination ladders (sometimes referred to as articulating ladders).

The first and second assemblies102and108may be formed of a variety of materials and by way of a variety of manufacturing techniques. For example, in one embodiment, the rails104and110may be formed of a composite material, such as fiberglass, while the rungs106and112and other structural components may be formed of aluminum or an aluminum alloy. In another embodiment, the rails104and110as well as the rungs106and112may be formed of an aluminum or aluminum alloy. In other embodiments, the assemblies102and108(and their various components) may be formed of other materials including other composites, plastics, polymers, metals and metal alloys.

An adjustable leg116is associated with each rail104of the first assembly102. The adjustable leg116is slidably coupled to its associated rail104and may include a foot118or other support member which may be coupled to the lower end thereof. A swing arm120has a first end that is pivotally coupled with and associated adjustable leg116at a location between the upper and lower ends of the adjustable leg116. A second end of each swing arm120is pivotally coupled with an associated side rail104, or with a bracket122that is associated with the first assembly102(e.g., coupled to an associated rail and/or rung). In the embodiment shown inFIGS. 1 and 2, the location of the pivot (connecting the swing arm120and the bracket122) is positioned laterally inward of the associated side rail104(or between the two side rails104) and beneath the lowermost rung when viewing the ladder in an orientation of intended use such as shown inFIGS. 1 and 2.

The swing arms120may be configured as a non-linear member. For example, in one embodiment, each of the swing arms120may be configured to include a first section124and a second, shorter section126extending from the first section124at a desired angle β relative to first section124. In one example, the angle β may be between approximately 60° and approximately 179°. In another embodiment, the angle β may preferably be between approximately 100° and approximately 140°. In another embodiment, the angle β may more preferably be between approximately 115° and 125°.

Generally speaking, in the embodiment shown inFIGS. 1 and 2, the second section126may extend at an obtuse angle relative to the first section124. In other embodiments, the swing arm120may be configured as a curved member rather than two or more sections having an angular arrangement. In such a case, the curved member need not exhibit a common radius throughout its extent. Rather, the curved member may exhibit sections having different radii.

It is noted thatFIG. 1shows one adjustable leg116at a first position, and the other adjustable leg116at a second position. More specifically, the adjustable leg116shown on the right side of the drawing is positioned at a first angle (relative to its rail104), with the associated foot118being positioned at a first distance from the lowermost rung106of the first assembly102. On the other hand, the adjustable leg116shown on the left side of the drawing is positioned at a second angle (relative to its rail104), which is less than the first angle, and with its associated foot118being positioned at a second distance from the lowermost rung, the second distance being less than the first distance. The adjustable legs116are adjustable independent of one another and may be positioned at any of a range of positions, including a position where the adjustable arm is substantially parallel to its associated rail (positioned adjacent the rail) with its associated foot118being closer to the lowermost rung106than either of the positions shown inFIG. 1. Thus, as the upper end of an adjustable leg116slides along the length of a rail104, the swing arm120rotates and causes the angle of the adjustable leg116to change, the associated foot118simultaneously changing its distance from the lower most rung106.

Referring briefly toFIG. 2, the adjustable leg116shown on the left is deployed at a desired position, while the adjustable leg116shown on the right is in a fully retracted position. While the ladder100may be used with the leg116in a fully retracted position, it is contemplated that such a position will be utilized more for purposes of storage and transportation of the ladder100, making it smaller and more compact when not in use.

Considering the embodiment shown inFIGS. 1 and 2, the configuration of the first and second sections124and126of the swing arm120, including their respective lengths, the angle at which they extend from one another, and their pivot locations relative to their associated rails104and adjustable legs116, may be selected to effect a desired angular position of the adjustable legs116when the upper end of the adjustable legs is displaced along the length of their associated rails104.

Further, such parameters may be selected provide a desired rate at which the foot118is displaced laterally away from its associated side rail104and a desired rate at which the foot is displaced vertically relative to the rungs106when the upper end of the adjustable leg116is displaced upwards or downwards along its associated side rail104. The nonlinear configuration of the swing arm120permits the lateral displacement and the vertical displacement of the foot118to be controlled in a desired manner. For example, the components may be arranged such that when being displaced from a fully collapsed or stored state to a deployed state, the foot118is initially displaced primarily laterally, away from the side rail104, in order to provide greater width and stability immediately, providing a curved pathway128of the foot118that is nonlinear and may be geometrically complex.

Thus in one example, initial displacement of the upper end of the adjustable leg116may result in a foot path having a lateral or horizontal displacement indicated by H1and a vertical displacement of V1as indicated inFIG. 2. Further displacement of the upper end of the adjustable leg116may then result in primarily vertical displacement of the foot118while the foot118remains within a “lateral zone.” Thus in one example, further displacement of the upper end of the adjustable leg116may result in a foot path having a lateral or horizontal displacement indicated by H2and a vertical displacement of V2as indicated inFIG. 2. This enables the ladder to gain immediate stability with a broader base, while providing subsequent vertical adjustment while the foot118remains within a range of desired distances from the side rail104.

In one particular example embodiment, the pivot location between the swing arm120and the bracket122may be positioned a distance D1approximately 2.25 and 2.5 inches inwardly from the outer surface of its associated side rail104. The first section124of the swing arm120may be approximately 6.75 to 7.0 inches long and the second section126may be approximately 3.25 to 3.5 inches long and the angle β may be approximately 117°. Considered another way, the example embodiment includes a swing arm120where the length ratio of the first section124to the second section126may be approximately 2:1 or greater. Of course, other dimensions and configurations are contemplated and this example is not to be considered limiting in any sense.

Referring toFIGS. 1 and 2in association withFIG. 3, an adjustment mechanism130is associated with each adjustable leg116in order to effect the selective displacement of the upper end of the adjustable leg116relative to the rail104. For example, the upper end of the adjustable leg116may be pivotally coupled to a sliding body132of the adjustment mechanism130. The sliding body132may be slidably coupled to a rod or a bar134which is coupled to the rail104such that it is spaced apart from, but extends substantially parallel to, the rail104. An actuator button136may be associated with the body132to selectively effect locking and release of the sliding body132relative to the bar134as will be discussed in further detail below. In one embodiment, the adjustment mechanism130may be configured such that sliding the actuator button136upwards (when in the intended operating orientation of the ladder, such as shown in FIG.1,) enables the body132to slide upwards along the bar134, but not downwards along the bar134. Additionally, sliding the button136downwards enables a user to slide the body132downwards along the bar134but not upwards along the bar134.

Such a configuration makes operation of the adjustable leg116more intuitive for a user of the ladder100. For example, pushing the button136downwards to adjust the body132and, thus, the leg116and foot118downwards. In effecting such an adjustment, a user might have to hold or “lift up” on, for example, the first assembly102while the body132is slid downwards, resulting, ultimately, in the foot118being displaced generally downwards and outwards. Likewise, sliding the button136upwards enables a user to slide the body132and, thus, the adjustable leg116and foot118upwards.

It is noted that such a configuration may act as a safety mechanism as well. For example, if something falls on and inadvertently displaces the button136downwards, the sliding body132will not travel upwards relative to the bar134and rail104. Inadvertent travel of the body132upwards relative to the bar134and rail104would, due to gravity, cause the rail104and rungs106to “fall” downwards and create an unstable situation for a user on the ladder100.

Referring now toFIG. 4, an adjustment mechanism130is shown in accordance with an embodiment of the present invention. It is noted that the adjustment mechanism130is shown inFIG. 4with a cover associated with the body132removed to show the internal components. As seen in the various drawings, the bar134may include longitudinal edge surfaces142having frictional or traction surface features. For example, the surface features may include notches, knurling, an undulating surface or a roughened surface.

The adjustment mechanism130includes a first set of engagement plates150having a first end152positioned in a seat154formed within the body132. A biasing member156that provides a biasing force between a surface of the body132and the engagement plates150such that the second end158of the engagement plates150are biased in a first direction (downward in the orientation shown inFIG. 4). The adjustment mechanism130includes a second set of engagement plates160having a first end162positioned in a seat164formed within the body132. A biasing member166provides a biasing force between a surface of the body132and the engagement plates160such that the second end168of the engagement plates160are biased in a second direction, substantially opposite of the first direction (i.e., upward in the orientation shown inFIG. 4).

Each of the engagement plates150and160include an opening170formed therein, as seen inFIG. 5. The opening170is sized and configured such that the rod or bar134extends through the openings of the various engagement plates150and160. The opening170includes an engagement surface172that is configured to selectively engage and disengage a longitudinal edge surface142of the rod or bar134including the surface or traction features of the longitudinal edge if the bar134includes such.

Still referring toFIG. 4, the adjustment mechanism130includes an actuating plate180having a first end182pivotally seated or coupled with the body132and a second end184extending out of the body132for engagement with an actuating button136(not specifically shown inFIG. 4) or for use as the actuating button. The actuating plate180may include an opening through which the bar134extends, similar to engagement plates150and160. However, the opening in the actuating plate180is not configured to engage a longitudinal edge surface of the bar134. As depicted inFIG. 4, the adjustment mechanism130is in a neutral or completely locked state such that the body132can not slide in either direction along the bar134. This is because the engagement surface172of the first set of engagement plates150is biased into engagement with a longitudinal edge surface142of the bar134, preventing the body132from being displaced upwards along the bar134(in the orientation shown inFIG. 4), while the engagement surface172of the second set of engagement plates160is biased into engagement with the longitudinal edge surface142of the bar134, preventing the body132from being displaced downwards along the bar134(in the orientation shown inFIG. 4).

Referring toFIG. 6, the adjustment mechanism130is shown with the actuation lever180displaced upwards, causing the first set of engagement plates150to be pivoted upward such that their engagement surfaces172are no longer engaged with longitudinal edge surface142of the bar134. This enables the body132to slide upwards along the bar134. The second set of engagement plates160permit the body132to slide upwards along the bar134because they do not “bite” into the longitudinal edge surface142of the bar when travelling in that direction. However, the second set of engagement plates160still prohibit the body132from being displaced downward along the bar134when in the state shown inFIG. 6.

Referring toFIG. 7, the adjustment mechanism130is shown with the actuation lever180displaced downwards, causing the second set of engagement plates160to be pivoted downward such that their engagement surfaces172are no longer engaged with longitudinal edge surface142of the bar134. This enables the body132to slide downwards along the bar134. The first set of engagement plates150permit the body132to slide downwards along the bar134because they do not “bite” into the longitudinal edge surface142of the bar134when the body132is travelling in that direction. However, the first set of engagement plates150still prohibit the body132from being displaced upward along the bar134when in the state shown inFIG. 7.

It is noted that the embodiment described herein contemplates a bar134that exhibits a substantially rectangular cross-section taken substantially transverse to the length thereof. However, other shapes are also contemplated including round, oval, square and other geometries. Also, while specific components, or a specific number of components are shown in the drawings, such should be considered as an example only and not limiting. For example, while the biasing member is shown as a coil spring, other biasing members may be used. Similarly, while the engagement plates are shown in sets of two, other numbers of plates may be used.

Referring now toFIG. 8, an adjustment mechanism136is shown in accordance with another embodiment of the present invention. The adjustment mechanism130includes a first set of engagement plates150having a first end152positioned in a seat154formed within the body132. A biasing member156that provides a biasing force between a surface of the body132and the engagement plates150such that the second end158of the engagement plates150are biased in a first direction (downward in the orientation shown inFIG. 8). The adjustment mechanism130includes a second set of engagement plates160having a first end162positioned in a seat164formed within the body132. A biasing member166provides a biasing force between a surface of the body132and the engagement plates160such that the second end168of the engagement plates160are biased in a second direction, substantially opposite of the first direction (i.e., upward in the orientation shown inFIG. 8). Each of the engagement plates150and160may be configured such as described above with respect toFIG. 5.

The adjustment mechanism130includes an actuating button190or lever having a pair of angled surfaces192and194configured to abut or otherwise engage the second ends of the first set of engagement plates150and second set of engagement plates160, respectively. As depicted inFIG. 8, the adjustment mechanism130is in a neutral or completely locked state such that the body132can not slide in either direction along the bar134. This is because the engagement surface172of the first set of engagement plates150is biased into engagement with a longitudinal edge surface142of the bar134, preventing the body132from being displaced upwards along the bar134(in the orientation shown inFIG. 8), while the engagement surface172of the second set of engagement plates160is biased into engagement with the longitudinal edge surface142of the bar134, preventing the body132from being displaced downwards along the bar134(in the orientation shown inFIG. 8).

Referring toFIG. 9, the actuating button190is depressed into the body132such that the angled surfaces192and194engaged and displace both the first and second sets of engagement plates150and160substantially simultaneously away from each other. This results in the engagement surfaces172(of both sets of engagement plates150and160) disengaging the longitudinal edge surface142of the barn134, enabling the body to slide in either direction (i.e., upwards or downwards) along the bar134. Releasing the actuating button190allows the engagement plates150and160to return to their original, engaged position, such as shown inFIG. 8, so that the body132is again locked in position along the bar134.

As previously noted, the adjustment mechanism may be used in conjunction with a variety of ladder types. For example, the adjustment mechanism and/or associated components (e.g., adjustable leg, swing arm, etc.) may be used in association with, or combined with components from, the ladder described in U.S. Pat. No. 8,365,865 (issued Feb. 5, 2013, entitled ADJUSTABLE LADDERS AND RELATED METHODS), the disclosure of which is incorporated by reference herein in its entirety. Additionally, such may be used in conjunction with a step ladder or with the types of ladders described in U.S. Pat. No. 8,186,481 (issued May 29, 2012, entitled LADDERS, LADDER COMPONENTS AND RELATED METHODS) or U.S. Pat. No. 4,182,431 (issued Jan. 8, 1980, entitled COMBINATION EXTENSION AND STEP LADDER RUNGS THEREFOR [sic]), the disclosures of which are incorporated by reference herein in their entireties.

Additionally, other adjustment mechanisms may be used to effect the selective positioning of the upper end of the adjustable arms along the length of the side rails. For example, additional examples of adjustment mechanisms that may be used in conjunction with the adjustable legs and associated swing arms include those described in U.S. Provisional Patent Application No. 61/874,882, filed on Sep. 6, 2013, entitled ADJUSTABLE LADDERS, LADDER COMPONENTS AND RELATED METHODS, the disclosure of which is incorporated by reference herein in its entirety.

Features and aspects of one embodiment may be combined with features and aspects of other embodiments without limitation. 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, 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.