The present invention relates to the field of ladders or ladder platforms or extensions which are intended to improve the safety of a user.
Ladders with extended rails at the top are well known in the art. Attachable rail extensions are also known. U.S. Pat. No. 7,322,442 B2 by Clark et al. issued on Jan. 29, 2008 teaches walk through side bar extensions which are attached to the top portion of the rails in a variety of ways including bolts, clamps, sliding hooks and the like. U.S. Pat. No. 5,941,343 by Kelsey issued on Aug. 24, 1999 teaches vertical hand rail extensions which attach to the ladder by sliding over the top of the ladder side rails in a telescoping fashion and are secured thereto by pins or bolts providing extension arms attached with brackets to the top portion of the ladder and supported on a roof by feet for extra stability.
A ladder is typically used to reach high locations on buildings and other structures and particularly used to gain access to the roof of such structures. The common ladder is made up of longitudinal rails with rungs disposed therebetween along the longitudinal length of the rails whereby the ladder legs rest on the ground and the top portion is extended to lean against a roof or other supporting member at an angle of about 75 degrees (typically providing a ratio of about a 4:1 vertical to horizontal distance). Two or more ladder sections can be combined and co-operatively engaged to form an extension ladder. An extension ladder makes it possible for a person to reach higher areas of a structure with a ladder that can be extended to nearly twice its length.
Thus, because of a ladder's design, the upper end is inherently prone to slipping caused by even the slightest movement by one positioned on the upper part of the ladder, especially when the angle of inclination is close to vertical.
In addition, using a ladder to access a roof poses other problems. Oftentimes, a ladder is just tall enough to reach the edge of a roof. Typically, and in accordance with governmental safety regulations, the upper most part of the ladder must extend above the edge of the roof so that a person can adequately step onto the roof. The Occupational Safety and Health Administration in 29 C.F.R. Section 1926.1053(b)(1) specifies that where portable ladders are used for access to an upper landing surface, the ladder side rails shall extend at least three feet above the upper landing surface to which the ladder is used to gain access.
In order for a person to access the roof when exiting a typical ladder, he must climb around one of the side rails of the ladder, which creates a situation where the ladder will likely be pushed away from the user and possibly fall away from the roof. In addition, the safety of the person can be compromised at that moment, since the person may rely on the ladder rails to hang onto while stepping from the ladder onto the roof.
These conditions also occur when a person is merely using the ladder to reach high locations. For example, when using a ladder on a typical residential house, the upper most part of the ladder is typically leaned against the outer edge of the gutter. Besides the fact that a ladder is likely to slip against the edge of a gutter, gutters are typically not rigid enough to give good support to a ladder and its user.
The present invention provides extension arms which are permanently and pivotally attached to the outer sides of the rails of the ladder at a point close to the top rung. At the top of the ladder, the user can swing each of the arms into one of a plurality of positions, typically to a point where the arms are nearly vertical and then lock the arms into place. The arms can be provided with non-slip grips to enhance a users grip during climbing.
Additionally, a step plate is pivotally connected to the top rung such that with the top rung just above the edge of the roof, the plate can be pivoted over and rests on the roof, thus providing a generally horizontal safety step or platform which also tends to hold the ladder from slipping as the user walks through the arms or side rails of the platform and off onto the roof or other structure. Another advantage provided by the step plate is that is covers the gutter. This protects the gutter from being stepped on but more importantly protects the user from stumbling on the gutter and possibly falling. In order to allow the step plate to be level when it is pivoted down onto an elevated surface, it's length may be adjustable. For example, it may be composed of two plates held together with screws in long slots or nested one within the other which allow the plates to telescope and extend the length with respect to one another.
Further, the bottom outer edge of the step plate where the plate comes into contact with the roof can have a non-skid coating which would help prevent slippage of the entire ladder relative to the roof.
At least one preferred embodiment of the present invention comprises, consists essentially of or consists of a ladder used to gain access to an elevated surface by inclining the ladder against an outer edge of the surface. The ladder has a pair of laterally spaced apart rails interconnected by vertically spaced apart rungs, and includes a pair of rotary units pivotally attached on an outer side of a top portion of the rails. Each of the rotary units have an arm member fixed to the rotary unit extending outward from the rotary unit and parallel to the rails. the rotary units are capable of being locked in any of several selected positions. One of the positions causes the arms to be held in a storage/transport position. Another of the positions causes the arms to be held in an upright position for providing a walk through passageway providing safe ascent to and descent from the elevated surface. A step plate is hingedly attached to a top rung of the ladder wherein the step plate can be held in a storage/transport position or can be swung down onto the elevated surface to provide a safety step.
Another embodiment of the present invention comprises, consists essentially of or consists of a safety accessory kit for a ladder used to gain access to an elevated surface by inclining the ladder against an outer edge of the surface. The ladder has a pair of laterally spaced apart rails interconnected by vertically spaced apart rungs. The kit includes a pair of ladder rail engaging members configured to slidably receive a top portion of the rails. The members have formed therein a slot for slidably receiving a top rung of the ladder and the members including a rotary unit having an arm member fixed to the rotary unit and extending outward from the rotary unit and parallel to the rails. The rotary units are capable of being locked in any of several selected positions. One of the positions causes the arms to be held in a storage/transport position. Another of the positions cause the arms to be held in an upright position for providing a walk through passageway providing safe ascent to and descent from the elevated surface. A step plate is configured to be hingedly attached to a top rung of the ladder wherein the step plate can be held in a storage/transport position or can be swung down onto the elevated surface to provide a safety step. At least two hinge assemblies are provided for hingedly attaching the step plate to the top rung of the ladder.
It is an object of the present invention to provide a ladder which provides a safe way of ascending onto and descending from the roof of a structure.
It is an object of the present invention to provide an extension accessory for a ladder which pivots down to a storage and transport position and pivots up and locks into an approximately vertical position to provide arms and handles which a user can walk through safely onto a selected surface.
It is also an object of the present invention to provide a non-skid step plate which pivots on the top rung of a ladder onto a roof edge to provide stability to the ladder and to protect gutters.
It is another object of the present invention to provide a walk through ladder apparatus that is inexpensive to produce.
It is another object of the present invention to provide a ladder safety apparatus that is reliable even after rigorous and extended use.
A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the views wherein:
In accordance with the present invention, there is provided a ladder 12 with a walk through top portion having a pair of pivoting arms 32 extending from the distal ends of the ladder rails 10 providing selectively angled holding rails and a safety step plate 20 pivotally attached to the top rung 14 of the ladder 12.
As illustrated in
Rotary locking units 30 supporting the swing arms 32 include interlocking rotating disks. Disk 37 is attached to rail 10 and disk 35 is attached to the housing 38 which is also attached to the swing arm 32. A means for tightening and locking defining a threaded bolt 36 cooperatively engaging a threaded bore extending through the discs 35, 37 and engaging a rail 10 of the ladder 12 or a frame or housing secured to the ladder rail 10 is used to bias disk 35 and disk 37 together in a cooperative engagement position such that one disk cannot rotate with respect to the other. Therefore, swing arm 30 cannot rotate relative to rail 10. Moreover, if desired the swing arm 32 on one side of the ladder can be positioned at a different from that of the opposing swing arm 32 allowing the swing arm to be used as an additional support and or stabilizing member in contact with the roof or other support structure.
Another embodiment of the present invention, shown in
A further embodiment, shown in
Another embodiment shown in
It is desirable that step 123 is level when using it to enter a roof or high level surface. This is made possible by making the length of step plate 123 adjustable. Another embodiment features the adjustable step plate 123 whose length is adjustable. With screws 125 loosened, plate 127 may slide toward plate 124 to shorten step 123, or it may slide away from plate 124 to lengthen step 123. Slots 129 allow sliding of screws 125. Screws 125 are tightened into nuts 128 to lock step plate 123 at a selected length. It is anticipated that threaded holes within plate 127 could replace nuts 128.
The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modification will become obvious to those skilled in the art upon reading this disclosure and may be made upon departing from the spirit of the invention and scope of the appended claims. Accordingly, this invention is not intended to be limited by the specific exemplification presented herein above. Rather, what is intended to be covered is within the spirit and scope of the appended claims.