Adjustable ladder support mechanism

The disclosed adjustable ladder support mechanism solves the problem of unstable extension ladders with a mobile base that can be moved by one man, the base then expanded in both length and width. With the stable base set up, the ladder can be extended, the angle adjusted, and the operator can safely climb the ladder. Worries of the ladder slipping sideways off the ledge against which it is leaned are eliminated.The adjustable ladder support mechanism has two main sections: the base, which provides stability, and the tower, which raises the ladder above the ground.

FIELD

This invention relates to the field of ladders and more particularly to an adjustable mechanism for supporting a ladder, such as an extension ladder.

BACKGROUND

Ladders of various sizes, shapes, and uses are well known in the art. But for a professional who needs to perform many different elevated tasks, often many different ladders are required. A professional may need an A-frame ladder (step ladder) for free-standing work, an extension ladder for very high work, and a platform ladder for horizontal elevated work. It is inconvenient and expensive to store and transport this many ladders.

What is needed is a ladder system that provides adjustability and versatility to allow many uses of a single ladder.

SUMMARY

Elevated work often requires the use of an extension ladder. But the unsteady nature of extension ladders makes such work hazardous. A-frame ladders, while more stable, are unavailable in heights above twenty feet. Thus, higher work necessitates either scaffolding or an extension ladder. The disclosed adjustable ladder support mechanism solves the problem of unstable extension ladders with a mobile base that can be moved by one man, the base then expanded in both length and width. With the stable base set up, the ladder can be extended, the angle adjusted, and the operator can safely climb the ladder. Worries of the ladder slipping sideways off the ledge against which it is leaned are eliminated.

The adjustable ladder support mechanism has two main sections: the base, which provides stability, and the tower, which raises the ladder above the ground.

The Base

The base provides the platform for the adjustable ladder support mechanism. The footprint, or area of the supporting surface (e.g., ground, driveway, etc.) covered by the base, is supported at each corner by wheels. The footprint is expandable through movable outriggers, or movement of the supporting wheels themselves.

Each corner of the base moves outward to increase size of the footprint, and thus stability. Depending upon the embodiment, this expansion can be performed manually or by use of a powered system. If manually, it may be through a hand-cranked screw mechanism, if automated, through any type of linear actuator (e.g., mechanical actuators, hydraulic actuators, pneumatic actuators, piezoelectric actuators, electro-mechanical actuators).

The base allows for expansion through the use of sliding joints. The example embodiment uses nested box beams, one sliding into another, to allow for expansion/contraction of the base.

The wheels present at the corners are either mounted on a horizontal axle for rotation in a single direction, or allowing for spinning, such as is seen in casters.

The Tower

The tower rises from the base, substantially forming a shape resembling a capital letter “A.” A first set of legs of the tower is of a fixed length in the embodiment shown. The second set of legs can either be of a fixed length, or of an adjustable length. Adjustable length allows the legs to expand or collapse, changing the height and position of the peak of the tower.

In alternative embodiments, the first set of legs is also of variable length.

In an embodiment with legs of adjustable length, the sets of legs that make up the tower are hingedly attached to the base. The hinged connections can be of any type, although simple barrel hinges or pivot hinges are shown in the embodiment.

The sets of legs optionally include steps, allowing an operator to climb the steps of the adjustable ladder support mechanism to reach the extension ladder mounted at the peak of the tower.

Ladder Gripping Mechanism

At the peak of the tower is the ladder gripping mechanism, where the adjustable ladder support mechanism attaches to an extension ladder. The extension ladder used need not be a specific type, although the dimensions of the ladder gripping mechanism may need to be adjusted for unusually sized extension ladders.

The base section, or larger section, of the extension ladder is held by the ladder gripping mechanism. The fly section, or smaller section, is free to extend from the base mechanism.

The fly section of ladder is held in place relative to the base section of the ladder by rung locks, as are common in extension ladders.

The ladder gripping mechanism is hingedly attached to the tower. A linear actuator of any type (e.g., mechanical actuators, hydraulic actuators, pneumatic actuators, piezoelectric actuators, electro-mechanical actuators) is used to change the angle of the ladder gripping mechanism, and thus the angle of the ladder.

The ladder is held within the ladder gripping mechanism by a pin that passes through the ladder gripping mechanism itself and into a hole created in the extension ladder by the penetration of a ladder rung.

The chain drive is used to move the extension ladder through the ladder gripping mechanism. In order to use the chain drive the proximal end of the chain is affixed to the proximal end of the base section of the extension ladder. The ladder pin is pulled to release the base section of the extension ladder, and then the crank is turned to pull the proximal end of the chain, raising the ladder. When the ladder is in the desired location the ladder pin is reinserted.

Extension Ladder

As discussed, for most embodiments the extension ladder is separate. A standard extension ladder consists of a base section that generally rests on the ground, and a fly section that extends from the top of the ladder. Extension is often performed by attaching one end of a cord to a rung near the bottom of the fly section of the ladder, and running the cord through a pulley near the top of the base section of the ladder. Pulling the cord results in the fly section of the ladder being pulled upward. Once the fly section of the ladder is at its desired location, rung locks are used to lock the two sections of the ladder relative to one another.

Furthermore, optional ladder plates may be used to affix the base section and the fly section of the ladder together.

Ladder Rung Platform

The adjustable ladder support mechanism can also be used as a type of scaffolding. By lowering the angle of the ladder gripping mechanism to an angle near horizontal, and adjusting the length of the tower legs if needed, the extension ladder is used in a horizontal position and acts as a work platform.

But using a ladder in a horizontal position may result in the user stepping into the spaces between the rungs.

Folding Rung Covers

The adjustable ladder support mechanism optionally includes folding covers that provide a platform over the extension ladder. The folding rung covers are intended for use when the extension ladder is in a near-horizontal position and the spaces between the rungs are a danger, rather than a location for one's foot.

The folding rung covers are of any number of plates, connected to the extension ladder by hinges. The exemplary folding rung covers are comprised of two plates per cover, with a total of two covers being sufficient to fill the width of the extension ladder.

The folding rung covers are anticipated to use tracks integrated with the rungs that guide the folding rung covers from open to closed positions.

The folding rung covers are of sufficient strength to allow a user to walk on them.

Option handrails are also shown.

DETAILED DESCRIPTION

FIG. 1illustrates a side view of an embodiment of the adjustable ladder support mechanism. The adjustable ladder support mechanism1is shown, including its two main components of the base2and tower4. The exemplary embodiment of the tower4has two legs, a first tower leg6and a second tower leg8. The first tower leg6is shown as extending above the point at which it meets the second tower leg8, terminating at the ladder hinge10. Ladder hinge10connects the tower4to the ladder gripping mechanism50.

The tower6is shown connecting to the base2through optional hinges, specifically the first tower hinge12and the second tower hinge13. First tower hinge12and second tower hinge13are needed when the inclination sliding joint14is present. Inclination sliding joint14is any type of joint that allows the length of the second tower leg8to be altered. Inclination sliding joint14is shown as a slip joint, allowing the lower portion of second tower leg8to slide within the upper portion of second tower leg8. The position is then fixed using any number of known methods, including spring pins, bolts, etc.

The combination of the first tower hinge12, second tower hinge13, and inclination sliding joint14allows the inclination of the legs to be modified. Optionally, first tower leg8also incorporates a sliding joint (not shown).

The adjustable ladder support mechanism1can be used with extension ladders of great height, making tipping an issue. The base2of the adjustable ladder support mechanism1is equipped with multiple outriggers to increase stability before use. This includes front outriggers20and rear outriggers26/28. Front outriggers20are shown as increasing the length of the base2, although it is anticipated that front outriggers20can also be used to extend the width. Front outriggers are shown as contacting the ground through front wheels24.

Front outriggers20can be extended using extension linear actuator31, which increases the length of the base through the extension sliding joint30. Extension sliding joint30is any type of joint that allows the length of the base2to be altered. Extension sliding joint30is shown as a slip joint, allowing one portion of the base2to slide into another portion of the base2. The position is then fixed using any number of known methods, including spring pins, bolts, etc.

Rear outriggers26/28are shown extending the width of the base2, although it is anticipated that rear outriggers26/28can also be used to extend the width. Rear outriggers are shown with two sets of wheels, a first set of rear wheels26that are at a fixed position on the base, and a second set as part of the outrigger foot28. Outrigger foot28can be wheels, as shown in the exemplary embodiment, or a non-rolling end, such as a foot or pad. The wheels can be locking or non-locking.

The exemplary embodiment is shown with steps32that allow an operator to climb to the ladder.

Moving to the top of the tower4, ladder gripping mechanism50is shown (for clarity, shown inFIG. 4without the ladder). The ladder hinge10and ladder inclination linear actuator16work in combination to allow the ladder gripping mechanism50to alter the inclination angle62of the extension ladder80.

Referring toFIG. 2, an isometric view of an embodiment of the adjustable ladder support mechanism1is shown. Extension ladder80is shown, specifically the base section84and fly section82. Extension ladder80includes side rails86, which connect rungs88.

The locking mechanism between the fly section82and base section84is the standard rung lock90that is common to extension ladders. Furthermore, the rope and pulley system92common to extension ladders, used to extend the fly section82of the ladder80while at the base of the ladder80, remains operational.

Referring toFIG. 3, a side view of an embodiment of the adjustable ladder support mechanism, with the support in a horizontal position is shown. The adjustable ladder support mechanism1has the ability to hold the ladder in a horizontal position for use as scaffolding. Or, as shown inFIG. 3, to hold the extension ladder at an inclination angle62(seeFIG. 1) of zero degrees. The inclination linear actuator16operates to fix the inclination of the ladder gripping mechanism50, and the legs6/8of the tower2optionally include vertical adjustability to support changes in the elevation of the extension ladder80.

Optional ladder plates77are shown affixing the fly section82of the extension ladder to the base section84.

Referring toFIG. 4, a close-up of ladder gripping mechanism50is shown. The base section84of the extension ladder80is held by the ladder gripping mechanism50. The base section is held between the lower ladder rest surface52and the upper ladder rest surface54. Ladder pin66connects the ladder gripping mechanism50to the base section84of the extension ladder80by penetrating a hole created in the sidewall86by a rung88.

Drive chain56is operated by drive gear58, in turn rotated by crank110on axle111. Drive chain56is supported by carrier gears60. Axle111also rotates an additional drive gear (not shown) on the opposite side of the ladder gripping mechanism50.

The drive chain56has two ends, a chain proximal end68and a chain distal end70. Chain proximal end68is affixed to the proximal end of the base section84of the extension ladder80. The ladder pin66is pulled to release the base section84of the extension ladder80, and then the crank110is turned to reduce the length of chain between the chain proximal end68and the crank110, acting to pull the proximal end68of the drive chain56, thus raising the extension ladder80. When the extension ladder80is in the desired location the ladder pin66is reinserted.

Referring toFIG. 5, a view of the optional folding rung covers120for the ladder rungs is shown.

The exemplary folding rung covers120include an inner plate100connected to the side rail86by an inner hinge104, and to the outer plate102by an intermediate hinge106. The hinges104/106are any type of hinge, but likely to be a type of continuous hinge, commonly known as a piano hinge.

The inner plate102is held in alignment by interfacing with one or more tracks108mounted on, or intrinsic to, rungs88.