Fire escape – ladder – or scaffold – Ladder – Supporting surface compensating means
Reexamination Certificate
2002-05-01
2003-07-22
Chin-Shue, Alvin (Department: 3634)
Fire escape, ladder, or scaffold
Ladder
Supporting surface compensating means
C182S108000
Reexamination Certificate
active
06595326
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the general art of ladders, and to the particular field of ladder leveling devices.
2. Discussion of the Related Art
In nearly any construction project, a worker is required to stand on a ladder to complete a job. This requirement applies to painters, plasterers, electricians, carpenters and the like. While standing on a ladder, the worker must balance himself as well as complete the job which may tend to unbalance his stance on the ladder. Any unbalance on a ladder is not desirable.
However, many construction sites have uneven ground. A ladder resting on such uneven ground may not be as stable or as steady as possible thus distracting the worker, or worse.
Therefore, there is a need for a ladder that can be made stable on all ground configurations.
Often, a ladder is used next to a stairway or even on a roof. In such cases, the ladder may have to rest on two distinct levels. Certainly, the ladder must be stable. However, in a multi-level situation, it may not be possible to support a ladder in a manner that is as stable as desirable.
Therefore, there is a need for a ladder that can be leveled and stabilized for a wide range of terrain and support surface configurations.
While there are many examples of ladder leveling devices in the art, many of these devices are not as successful as they could be because they are not easy to use, or are not as stable as possible. For example, if the leveling device is not as securely attached to the ladder as possible, it may slip or move which is not desirable. Also, if the leveling device is complicated, it may be prone to failure, or expensive or difficult to attach or use. In any of these cases, the device will have drawbacks that inhibit its acceptance. If the device is complicated, it may be susceptible to malfunctioning due to dirt or the like. Since many ladders are used in situations where there is a great deal of dirt and/or dust, if the leveling device is susceptible to malfunctioning due to dirt and/or dust, the device will have shortcomings that may prevent its acceptance. Also, if the device being used to level a ladder is heavy and bulky, a worker may not use it due to the difficulty of maneuvering either the device or the ladder with the device attached.
Still further, it is desirable for a ladder leveling device to be amenable for use with a wide variety of ladders. If a ladder must be specially designed to accommodate the ladder leveling device, the device may not be widely accepted. If a ladder must be specifically re-designed to accommodate a ladder leveling device, it is likely that the leveling device will not be used.
PRINCIPAL OBJECTS OF THE INVENTION
It is a main object of the present invention to provide a ladder leveling unit that is easily attached to the ladder.
It is another object of the present invention to provide a ladder leveling unit that is easily adjusted with respect to the ladder being leveled.
It is another object of the present invention to provide a ladder leveling unit that is secure and stable once attached.
It is another object of the present invention to provide a ladder leveling unit that is amenable for use with a wide variety of terrain configurations.
It is another object of the present invention to provide a ladder leveling unit that is easily used on a wide variety of ladders.
It is another object of the present invention to provide a ladder leveling unit that can be easily adapted to an existing ladder.
It is another object of the present invention to provide a ladder leveling unit that is not overly expensive.
It is another object of the present invention to provide a ladder leveling unit that is not overly bulky.
SUMMARY OF THE INVENTION
These, and other, objects are achieved by a ladder leveling unit that includes a leg unit having a plurality of spaced apart holes defined therethrough and a foot unit fixed thereon. The leg unit is attached to a ladder by a lock unit that includes a U-shaped bracket and a spring-loaded lock that has a spring-biased bolt with a handle on one end and a stop flange thereon. A U-shaped body mounts the bolt and has a stop element thereon for holding the bolt in a releasable configuration. Bolt-accommodating holes are defined in the unit and in the ladder and the bolt extends through a selected hole in the unit into a hole defined in the ladder to attach the leveling unit to the ladder at a selected position.
The unit of the present invention is easily attached to a ladder and permits a wide range of height selections to be made while being stably and securely held in the selected position. Once attached to a ladder, the leveling unit will be quite stable and thus the ladder will be stable.
REFERENCES:
patent: 1329740 (1920-02-01), Barron
patent: 2147052 (1939-02-01), Noone
patent: 2449609 (1948-09-01), Linder et al.
patent: 2936849 (1960-05-01), Larson
patent: 3173512 (1965-03-01), Sturdy et al.
patent: 3233702 (1966-02-01), Feltrop
patent: 3554321 (1971-01-01), Stedman
patent: 3948352 (1976-04-01), Larson et al.
patent: 4249638 (1981-02-01), Fernandez
patent: 4683980 (1987-08-01), Vayko
patent: 4807720 (1989-02-01), Kim
patent: 5044468 (1991-09-01), Worthington, Jr.
patent: 5771992 (1998-06-01), Snyder
patent: 5791438 (1998-08-01), Kempton
Chin-Shue Alvin
Schoonover Donald R.
LandOfFree
Ladder leveling device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ladder leveling device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ladder leveling device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3062712