The present invention relates generally to a removable attachment for each leg of a ladder, and more particularly to a removable attachment to each leg of a ladder and each removable attachment extends a height of each leg of the ladder to adjust and compensate for uneven surfaces and includes a stabilizer arm to provide stabilization to the ladder.
In construction, painting, utility servicing, building maintenance and other occupations where a ladder is used to perform work, the placement of the ladder is often a problem. For example, the ladder may need to be placed upon uneven or inclined surfaces for work to be performed, such as on a stair, which results in rails of the ladder not being positioned vertically leading to the ladder falling. To position the rails of the ladder vertically to reduce injury, a ladder leveling device may be used.
The present application provides an adjustable extension for a ladder leg having an outer housing, an inner housing movable longitudinally relative to the outer housing in first and second directions opposite one another, and a stabilizer arm pivotably coupled to and movable with the inner housing. The stabilizer arm is pivotable about an axis perpendicular to the first and second directions such that the stabilizer arm is rotated relative to the inner housing to contact a surface to stabilize the extension in a sideways direction perpendicular to the first and second directions.
According to one aspect, an adjustable extension for a ladder leg is provided that includes an outer housing, an inner housing movable longitudinally relative to the outer housing in first and second directions opposite one another, and a stabilizer arm pivotably coupled to and movable with the inner housing, the stabilizer arm being pivotable about an axis perpendicular to the first and second directions such that the stabilizer arm is rotated relative to the inner housing to contact a surface to stabilize the extension in a sideways direction perpendicular to the first and second directions.
According to another aspect, an adjustable extension for a ladder leg is to provided that includes an extension leg movable longitudinally relative to the ladder leg in first and second directions opposite one another, and a stabilizer arm having a first end and a second end and being a fixed length, the stabilizer arm being pivotably coupled to the extension leg at the first end and movable with the extension leg, wherein the stabilizer arm is rotatable relative to the extension leg to contact a surface to stabilize the extension in a sideways direction perpendicular to the first and second directions.
According to still another aspect, a stabilizer system is provided that includes a stabilizer arm having a first end and a second end and being a fixed length, and a shoe connected to the second end of the stabilizer arm for gripping a surface when the stabilizer arm is in a deployed position, wherein the stabilizer arm is configured to be pivotally coupled to a ladder or ladder extension at the first end of the stabilizer arm, and wherein the stabilizer arm is movable between a stowed position substantially parallel to the ladder or ladder extension and the deployed position wherein the stabilizer arm is rotated about an axis substantially perpendicular to the ladder or ladder extension to provide side to side stabilization.
The foregoing and other features of the application are described below with reference to the drawings.
The principles of the present application relate to stabilizing, extending, and leveling a leg of a ladder, and thus will be described below in this context. It will be appreciated that the principles of the application may be applicable to other apparatuses requiring stabilizing, extending, and leveling, such as scaffolding.
Referring initially to
Turning now to
As shown in
Referring now to
To lock the release lever 50 in position when the extension leg 22 is extended and a load is applied to the extension 10, a safety bar 70 is provided as shown in
Turning now to
The stabilizer arm 100 is movable between a stowed position shown in
The stabilizer arm 100 has a first end or bottom 110, a second end or top 112, and an aperture 114. A shoe 116 is attached to the arm 100 at the second end 112 to prevent/reduce slipping of the arm 100 when deployed, and a torsion spring 118 surrounds the pivot pin 102 to help push the sides of the arm 100 up during stowing. The shoe 116 may be attached to the arm 100 in any suitable manner, such as by one or more fasteners, such as rivet 108 shown in
As noted above, the stabilizer arm 100 is pivotally connected to the extension leg 22 by the pivot pin 102 at the first end 110, which also connects the release pedal 58 to the extension leg 22. The stabilizer arm 100 is also pivotally attached near the first end 110 to a first end 120 of a brace extrusion 122 having a pair of spaced rails 124 that provide support to the stabilizer arm 100 and allow the arm to be thinner and lightweight. As shown in
When the stabilizer arm 100 is moved to the deployed position, for example moved approximately one hundred thirty five degrees as shown in
Referring now to
The slide angles 126 each include a first guide slot 152 and a second guide slot 154. A rack segment 156 extends through the second guide slot 154 in each slide angle 126 and is configured to engage a respective rail 158 connected to and disposed in respective channels 160 in the extension leg 22 when the stabilizer arm 100 is being deployed. In an embodiment, the channels 134 and 160 may be parallel to each other and each has a side formed by a shared wall 162. The rack segments and rails may be any suitable material, such as stainless steel.
To move the stabilizer arm 100 from the stowed position to one of the deployed positions when a load is applied to the extension 100, the user pushes downward on a handle 140. The downward movement pushes down the second end 128 of the brace extrusion 122 and pushes out the first end 120 of the brace extrusion 122 and the stabilizer arm 100. To move the stabilizer arm 100 from the deployed position to the stowed position when the load has been removed from the extension 100, the user moves the movable handle portion 144 towards the fixed handle portion 142, thereby disengaging the rack segments 156 from the rails 158. The user can then pull upward on the handle 140 in the first direction, moving the slide angles 126 and the second end 128 of the brace extrusion upward and causing the stabilizer arm 100 to pivot about the pivot pin 102 and return to the stowed position.
In the illustrated embodiment, to disengage the rack segments 156, the extension includes a wire release 170 and a pair of spring clips 172. The wire release 170 is substantially U-shaped, with a base of the U being disposed between the fixed and movable handle portions 142 and 144 and being moved by the movable handle portion 144, and with arms 174 of the U being substantially parallel with the slide angles 126. Each arm 174 includes an outwardly extending portion 176 that extends through the first guide slot 152 in the respective slide angle 126, and a curved end portion 178 trapped between the respective spring clip 172 and the respective slide angle 126. Each spring clip 172 has an end coupled to the respective slide angle 126 by a suitable fastener, such as rivet 182, an opposite end coupled to the respective rack segment 156 by a suitable fastener(s), such as screws, a ramp portion 184 therebetween, and a finger 186.
When the movable handle portion 144 is moved towards the fixed handle portion 142 when there is no load, the wire release 170 is moved towards the fixed handle portion 142, causing the curved end portions 178 to move along the ramp portions 184 deflecting the spring clips 172 inward. The inward movement of the spring clips 172 moves the rack segments 156 inward to disengage from the rails 158.
Referring now to
When the safety bar 70 is moved longitudinally in the first direction when the extension is loaded, the angled tabs 78 of the safety bar 70 move the wedges 80 outward resulting in the rack segments 156 moving outward into engagement with the rails 158 when the rack segments 156 are moved in the second direction, for example when the arm 100 is at a desired angle relative to the extension leg 22. In the illustrated embodiment, the wedges 80 are movably secured to the extension leg 22 in respective slots 190 and 192 in the extension leg 22. Thus the wedges 80 are held in their outward positions by the safety bar 70, and can be moved inward when the load is removed.
In the illustrated embodiment, the wedges 80 rotate a pair of wing extrusions 200 causing the wing extrusions 200 to move the rack segments 156 outward, and the wedges 80 hold the wing extrusions 200 in position until the load is removed. The wing extrusions 200 each include a body 202 having a through passage for receiving a rod or spring pin 204, two of which are provided for each wing extrusion 200 in the illustrated embodiment, and a pair of substantially v-shaped wings 206 having an inner leg 208 contacted by the wedges 80 and an outer leg 210 that contacts the rack segments 156. The fingers 186 of the spring clips 172 guide the outer legs 210 and prevent over rotation of the wing extrusions. The wing extrusions 200 are connected to a hinge clip 212 that protects the components and that is connected to the slide angles 126, for example via the pins 204 received in openings in the hinge clip 212, and the wing extrusions 200 are pulled together at the end near the handle 140 by an extension spring 214.
When the load is applied and the stabilizer arm 100 is moved towards the deployed position, the wedges 80 contact the inner legs 208 to rotate the wing extrusions 200, causing the outer legs 210 to contact and urge the rack segments 156 outward to engage the rails 158 as the segments move in the second direction. The rack segments 156 then ratchet along the rails 158 until the extension arm 100 is in the desired deployed position, and the interaction of the teeth of the rack segments 156 and rails 158 prevent longitudinal movement of the rack segments 156 in the first direction. When the load is removed, the user moves the movable handle portion 144 relative to the fixed handle portion 142, thereby moving the rack segments 156 inward, causing the wing extrusions 200 to rotate and the inner legs 208 to move the wedges 80 inward. The extension spring 214 also serves to pull the wing segments 200 together to move the wedges 80 inward.
Alternative embodiments of the extension and/or stabilizer arm are now described. The stabilizer arm may be deployed manually or automatically, for example when or shortly after the load is applied, and the stabilizer arm may be stowed manually or automatically, for example when the load is removed. Additionally or alternatively, the stabilizer arm may be adjusted and/or lock automatically or manually. Additionally or alternatively, the stabilizer arm may be deployed by manually or automatically releasing a latch or magnet, and a delay switch may be used to delay deployment after the load is applied, for example for three to six seconds if automatic. Additionally or alternatively, the stabilizer arm may automatically disengage and be unlockable when the load is less than approximately five pounds. Additionally or alternatively, one stabilizer arm may travel up while the other travels down and when both have an equal load the arms lock automatically or manually, for example with a pneumatic or manually operated thrust mechanism having a thrust bar. Additionally or alternatively, a sprocket rotates and turns a rod that rotates the sprocket such that one side travels up and the other travels down depending on slope, and a pawl may be provided that slides up and down to lock the stabilizer arms. Additionally or alternatively, the stabilizer arm can have a sensor that detects if there is a load to engage/disengage the stabilizer arm, for example a sender, sensor, and receiver on the shoe that talk to each other. In an embodiment, the stabilizer arm may have a secondary pivoting joint between the pivot point and the shoe to assist with irregular surfaces and/or include a handle for manually moving the arm. The stabilizer arm may have any suitable length, such as between eight and forty inches. Additionally or alternatively, the ladder may include a c-channel in which a stabilizer brace is recessed and the stabilizer arm wraps around the c-channel to appear as the outside of the ladder.
The stabilizer arms are substantially perpendicular to the rails of the ladder when seated on the support surface to adjust for the slope of the surface and prevent the ladder from tipping to either side. The stabilizer arm may use a ratchet system as discussed above or another suitable system, such as a knob tightening system, a pin and hole system, an electric motor system such as with a screw drive, an automatic locking system, a cam system, etc. The stabilizer arms may alternatively be provided between the ladder and the elevated surface the top of the ladder rests on or on the opposite side of the ladder to prevent/minimize the ladder movement away from the elevated surface either at the top and/or bottom of the ladder. In an embodiment, the stabilizer arms may provide side, front, and/or back stabilization, either as separate arms, for example three separate arms on each side of the ladder, or as an integral unit. The stabilizer arm can support the entire load, some of the load, or none of the load regardless of slope.
In addition although a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Also, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in the detailed description and/or in the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.”
This written description uses examples to disclose the invention, including the best mode, and also to enable one of ordinary skill in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
In the specification and claims, reference will be made to a number of terms that have the following meanings. The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Approximating language, as used herein throughout the specification and claims, may be applied to modify a quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Moreover, unless specifically stated otherwise, a use of the terms “first,” “second,” etc., do not denote an order or importance, but rather the terms “first,” “second,” etc., are used to distinguish one element from another.
As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur—this distinction is captured by the terms “may” and “may be.”
The best mode for carrying out the invention has been described for purposes of illustrating the best mode known to the applicant at the time and enable one of ordinary skill in the art to practice the invention, including making and using devices or systems and performing incorporated methods. The examples are illustrative only and not meant to limit the invention, as measured by the scope and merit of the claims. The invention has been described with reference to preferred and alternate embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of the specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. The patentable scope of the invention is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differentiate from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
This application claims priority to and the benefit of U.S. Provisional Application Ser. No. 62/285,042 filed on Oct. 19, 2015 and U.S. Provisional Application Ser. No. 62/389,840 filed on Mar. 11, 2016. The entireties of such applications are incorporated herein by reference.
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62389840 | Mar 2016 | US |