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 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.
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.
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 ladder 100 shown in
The first and second assemblies 102 and 108 may be formed of a variety of materials and by way of a variety of manufacturing techniques. For example, in one embodiment, the rails 104 and 110 may be formed of a composite material, such as fiberglass, while the rungs 106 and 112 and other structural components may be formed of aluminum or an aluminum alloy. In another embodiment, the rails 104 and 110 as well as the rungs 106 and 112 may be formed of an aluminum or aluminum alloy. In other embodiments, the assemblies 102 and 108 (and their various components) may be formed of other materials including other composites, plastics, polymers, metals and metal alloys.
An adjustable leg 116 is associated with each rail 104 of the first assembly 102. The adjustable leg 116 is slidably coupled to its associated rail 104 and may include a foot 118 or other support member which may be coupled to the lower end thereof. A swing arm 120 has a first end that is pivotally coupled with and associated adjustable leg 116 at a location between the upper and lower ends of the adjustable leg 116. A second end of each swing arm 120 is pivotally coupled with an associated side rail 104, or with a bracket 122 that is associated with the first assembly 102 (e.g., coupled to an associated rail and/or rung). In the embodiment shown in
The swing arms 120 may be configured as a non-linear member. For example, in one embodiment, each of the swing arms 120 may be configured to include a first section 124 and a second, shorter section 126 extending from the first section 124 at a desired angle β relative to first section 124. 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 in
It is noted that
Referring briefly to
Considering the embodiment shown in
Further, such parameters may be selected provide a desired rate at which the foot 118 is displaced laterally away from its associated side rail 104 and a desired rate at which the foot is displaced vertically relative to the rungs 106 when the upper end of the adjustable leg 116 is displaced upwards or downwards along its associated side rail 104. The nonlinear configuration of the swing arm 120 permits the lateral displacement and the vertical displacement of the foot 118 to 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 foot 118 is initially displaced primarily laterally, away from the side rail 104, in order to provide greater width and stability immediately, providing a curved pathway 128 of the foot 118 that is nonlinear and may be geometrically complex.
Thus in one example, initial displacement of the upper end of the adjustable leg 116 may result in a foot path having a lateral or horizontal displacement indicated by H1 and a vertical displacement of V1 as indicated in
In one particular example embodiment, the pivot location between the swing arm 120 and the bracket 122 may be positioned a distance D1 approximately 2.25 and 2.5 inches inwardly from the outer surface of its associated side rail 104. The first section 124 of the swing arm 120 may be approximately 6.75 to 7.0 inches long and the second section 126 may 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 arm 120 where the length ratio of the first section 124 to the second section 126 may 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 to
Such a configuration makes operation of the adjustable leg 116 more intuitive for a user of the ladder 100. For example, pushing the button 136 downwards to adjust the body 132 and, thus, the leg 116 and foot 118 downwards. In effecting such an adjustment, a user might have to hold or “lift up” on, for example, the first assembly 102 while the body 132 is slid downwards, resulting, ultimately, in the foot 118 being displaced generally downwards and outwards. Likewise, sliding the button 136 upwards enables a user to slide the body 132 and, thus, the adjustable leg 116 and foot 118 upwards.
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 button 136 downwards, the sliding body 132 will not travel upwards relative to the bar 134 and rail 104. Inadvertent travel of the body 132 upwards relative to the bar 134 and rail 104 would, due to gravity, cause the rail 104 and rungs 106 to “fall” downwards and create an unstable situation for a user on the ladder 100.
Referring now to
The adjustment mechanism 130 includes a first set of engagement plates 150 having a first end 152 positioned in a seat 154 formed within the body 132. A biasing member 156 that provides a biasing force between a surface of the body 132 and the engagement plates 150 such that the second end 158 of the engagement plates 150 are biased in a first direction (downward in the orientation shown in
Each of the engagement plates 150 and 160 include an opening 170 formed therein, as seen in
Still referring to
Referring to
Referring to
It is noted that the embodiment described herein contemplates a bar 134 that 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 to
The adjustment mechanism 130 includes an actuating button 190 or lever having a pair of angled surfaces 192 and 194 configured to abut or otherwise engage the second ends of the first set of engagement plates 150 and second set of engagement plates 160, respectively. As depicted in
Referring to
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.
The present application claims the benefit of U.S. Provisional Application No. 61/756,168, filed Jan. 24, 2013, and U.S. Provisional Application No. 61/828,000, filed May 28, 2013, the disclosures of each of which are incorporated by reference herein in their entireties.
Number | Date | Country | |
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61756168 | Jan 2013 | US | |
61828000 | May 2013 | US |