The field of the disclosure is a handrail for a ladder.
Handrails serve to stabilize the balance of people standing or walking on a staircase, bathtub, shower, escalator, and ladder. Lachance [U.S. Pat. No. 4,425,984] discloses a removable handrail for a ladder. However, this and all identified ladder safety handrails in the marketplace do not have the combination of handrails substantially along the same plane with at least one ladder member to minimize the chances of ladder tip-over, along with a surface topology feature which maximizes handgrip, while having the possibility of being removable, and the possibility to extend or telescope for an extendable-style of ladder.
The present disclosure attempts to remedy all the previously mentioned issues with a novel, new safety handrail. This disclosure contains two main embodiments. One embodiment is for ladders with a single pair of side rails (hereinafter termed “EMB-L1P”). An alternative embodiment is for an extendable ladder comprising of two or more pairs of side rails (hereinafter termed “EMB-L2+P”).
For EMB-L1P, each safety handrail is placed parallel and close to a ladder side rail on substantially the same plane where said ladder side rails and rungs connecting said ladder side rails lie. Each safety handrail is constrained to its closest ladder side rail by a plurality of removable clamps and clamp-to-handrail links. The ladder that EMB-L2+P is designed for comprises of two or more ladders, each section comprising of a pair of ladder side rails and rungs connecting the side rails of each ladder. The overall length of this extendable ladder is stretched when one ladder, hereinafter called the fly ladder, is linearly displaced relative to the next lower section of the ladder so that the bottom of the fly ladder is raised toward the top of the next lower ladder. Likewise, the extendable safety handrails are attached alongside and can telescope longer with the fly ladder as the overall length of the extendable ladder is increased and vice versa when the extendable ladder is shortened in overall length. For both embodiments, the safety handrails can be further extended for some distance above the top of the ladder. The surface of all embodiments of the safety handrails preferably has a knurled surface to maximize handgrip. Said embodiments also cater to ladder embodiments which open like an A-frame or when at least two ladders are in contact with a ground surface, said sections are splayed apart by a finite angle less than 180 degrees, and said two sections intersect at some point above the ground surface.
The drawings are provided to facilitate understanding in the detailed description. It should be noted that the drawing figures may be in simplified form and might not be to precise scale. In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, down, over, above, below, beneath, rear, front, distal, and proximal are used with respect to the accompanying drawings. Such directional terms should not be construed to limit the scope of the embodiment in any manner.
SAFETY HANDRAIL FOR SINGLE MEMBER LADDER (
One clamp (3a) is placed at the bottom and another clamp (3b) is attached to the top of the side rail (2a). Each clamp (3a, 3b) is attached to a clamp-to-handrail link (4a, 4b respectively), that in turn is attached to the base ladder safety handrail (5). The endpoints of the base ladder safety handrail (5) are roughly near the endpoints of the side rail (2a) such that a substantial length of the side rail (2a) runs alongside the base ladder safety handrail (5) and is therefore substantially along the same plane as the single member ladder (10). Arranging as such reduces the chance of tip-over of said ladder (10) by keeping the operator's body close to the plane of said ladder (10). In another embodiment, intermediate clamps and “clamp-to-handrail links” (not shown) can be attached in between the two endpoint clamps (3a, 3b) if required for additional structural rigidity of the base ladder safety handrail (5).
An extendable top safety handrail (7) of slightly smaller diameter than the base ladder safety handrail (5) can extend further like a telescoping radio antenna to provide additional length beyond the top of the side rail (2a). This extendable top safety handrail (7) is situated at the opposite end of the feet of said ladder (10) that touches the ground surface. A tip (8) attached to the open end of the extendable top safety handrail (7) has a somewhat larger diameter than the extendable top safety handrail (7) to facilitate the operator gripping and telescoping the extendable top safety handrail (7). Optionally, the difference between the inner diameter of the base ladder safety handrail (5) and outer diameter of the extendable top safety handrail (7), where the former is slightly larger, is small enough to allow an interference fit and provide some resistance during extension and retracting. Once fully extended, an embodiment incorporating a locking mechanism can prevent inadvertent retracting of the extendable top safety handrail (7).
SAFETY HANDRAIL FOR EXTENDABLE LADDER (
On each side of the base ladder (10), at least two clamps (3a, 3b), at least two clamp-to-handrail links (4a, 4b), and a base ladder safety handrail (5) are implemented like the single member ladder embodiment (1) discussed in
Connected along the same directional axis to the base ladder safety handrail (5) for this embodiment is a fly ladder safety handrail (12). The transition portion (13) from said base ladder safety handrail to fly ladder safety handrail is such that the inner diameter of the base ladder safety handrail (5) is slightly larger than the outer diameter of the fly ladder safety handrail (12) where the diameter difference can optionally be small enough to allow a high friction interference fit and provide some resistance during extension and retracting. The top of the fly ladder safety handrail (12) is attached to clamp-to-handrail link (4c), which in turn is connected to a clamp (3c) at the side rail (2b) near the top of the fly ladder (11) as shown in
CONSTRUCTION AND JOINING: The preferred construction embodiment for the base ladder safety handrail (5), fly ladder safety handrail (12), and extendable top safety handrail (7) is solid circular or tubular cross-section aluminum. The preferred surface topology embodiment of the safety handrails (5, 7, and 12) is knurled (6) to improve grip over a smooth surface. The clamp-to-handrail link (4a, 4b, 4c) embodiment can have a solid circular, tubular, or thin shell cross-section and is preferably made from aluminum. Said clamp-to-handrail links (4a, 4b, 4c) are fixed with the base ladder safety handrail (5) or fly ladder safety handrail (12) by use of a fastener, adhesive, or weld. The base ladder clamp-to-handrail links (4a, 4b) are attached to the corresponding clamps (3a, 3b) by way of fastener, adhesive, or weld.
Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the embodiment. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiment as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the embodiment includes other combinations of fewer, more, or different elements, which are disclosed herein even when not initially claimed in such combinations.
The present application claims priority to provisional patent application No. 62/986,774 filed on Mar. 9, 2020, disclosures of which are incorporated herein at least by reference.
Number | Name | Date | Kind |
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4425984 | Lachance | Jan 1984 | A |
10101189 | Demski | Oct 2018 | B2 |
20050284699 | Fowler | Dec 2005 | A1 |
20110266402 | Parrish | Nov 2011 | A1 |
Number | Date | Country |
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212153948 | Dec 2020 | CN |
20301470 | Jul 2004 | DE |
202017000453 | Mar 2017 | DE |
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CN212153948U_Translation_Description_20230713_2127.pdf (Year: 2020). |
DE20301470U1_translation.pdf (Year: 2004). |
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20220259921 A1 | Aug 2022 | US | |
20240003188 A9 | Jan 2024 | US |
Number | Date | Country | |
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62986774 | Mar 2020 | US |