Locking safety platform for a ladder

This invention relates to an improved safety platform for attachment to a ladder. The locking means of the device is engaged and disengaged without the use of tools or complicated mechanical means. This enables the user to adjust the height of the attachment on the ladder while standing on the ladder above ground level. The platform of the invention is fixed in a generally horizontal plane to hold containers or like articles, or for use as a platform for a person to stand upon while working. The invention is ideally suited for use by painters and like persons who do exacting work at varying heights above ground level while standing on a ladder.

BACKGROUND OF INVENTION 
1. Field of Invention 
The invention relates to an attachment for a ladder, and more particularly, 
the invention is directed to an improved detachable platform which can 
easily be locked into position for use by painters and other laborers who 
require stable footing when working while standing on a ladder, especially 
when the work requires the laborer to stand on the platform for extended 
periods of time and at varying heights above ground level during the work 
activity. 
The invention further relates to an improved safety feature for ladder 
attachments which provides for locking the platform to the ladder. More 
particularly, the invention is directed to providing a mechanism for the 
attachment of the platform in a secure, fixed position, without the use of 
tools or complicated mechanical measures, which can be accomplished while 
the laborer is standing on a ladder rung at heights above ground level. 
The device, in its locked position, would fix the platform in a generally 
horizontal plane, enabling the laborer to have stable footing thereon, 
without any obstruction from the ladder attachment. The device can also be 
used to place containers or articles thereon for the laborer's use over 
extended periods of time. The invention is particularly suited for use by 
painters and other types of laborers who during the course of their work 
activity have to constantly adjust their height from ground level, yet 
require stable footing while accomplishing exacting work. 
The invention can be used for a variety of applications, and the method of 
construction of the device is more fully described herein. 
2. Description of the Prior Art 
Various prior art ladder attachment devices and ladders, and the like, as 
well as their apparatuses and the method of their construction in general, 
are known and are found to be exemplary of the U.S. prior art. They are: 
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Inventor U.S. Pat. No. 
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B. H. Ziegler and D. Betzner 
745,750 
C. M. Dollerhide 1,920,552 
K. C. Miller 2,500,559 
E. H. Chapman 3,511,338 
W. R. Lincourt 4,482,030 
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The Lincourt patent is for a safety platform which has L-shaped hooks used 
for attachment to the upper and lower rungs. Dollerhide shows a detachable 
ladder step secured to two rungs of the ladder; U-shaped hooks are used 
for securing the invention to the upper rung. Chapman's invention also 
utilizes U-shaped brackets, but uses them to secure the device to the 
lower rung; steel hooks secure the stand to the upper rung. This invention 
is particularly suited for supporting one end of a plank which at its 
opposite end is supported by a like ladder stand upon a ladder. 
The Miller patent is directed to a ladder platform wherein the base is 
pivotably secured to one rung and swinging hook means are adjustable to 
various positions by means of notched formations in the side flanges of 
the platform. 
Ziegler and Betzner disclose an extension ladder with a moveable and 
adjustable shelf which is also secured in place by hooks projecting from 
the shelf to two rungs of the ladder. The extension feature of the ladder 
employs a bracing mechanism to secure the extended ladder in its adjusted 
position; steel wires are drawn taut by means of nuts on the ends of bolts 
to the required tension for the purpose of forming a truss. 
These patents or known prior uses teach and disclose various types of 
ladders and ladder attachment devices of sorts and of various 
manufactures, and the like, as well as methods of their construction; but 
none of them, whether taken singly or in combination, disclose the 
specific details of the combination of the invention in such a way as to 
bear upon the claims of the present invention. 
SUMMARY OF THE INVENTION 
An object, advantage, and feature of the invention is to provide a novel 
ladder attachment that is safe and efficient in use, providing its user 
with a stable platform fixed at a generally horizontal plane for placement 
of containers or like articles, or, more especially, for use as a platform 
to stand upon while working at heights above ground level. 
Another object of the invention is directed further to a device providing 
for the easy locking of the attachment device into a desired position on 
the rungs of a ladder, and the easy removal thereof, without tools or 
complicated mechanical measures, while the user is standing on the ladder 
above ground level. This is a substantial improvement over existing 
devices whereby various types of hook assemblies or other convoluted means 
are utilized to suspend the ladder attachment on the ladder rungs. 
Another object of the invention is to provide a novel and improved 
construction of securing a ladder attachment, to wit, the employment of 
hinged, arcuate safety bracket members which are engaged to both the upper 
rung of a ladder as well as to support members attached to the rear of the 
platform and extending to the upper rung of the ladder. 
Another object of the invention is to provide a novel and improved method 
of construction of a ladder attachment whereby a locking mechanism is 
incorporated therein, allowing for the required stability essential for 
supporting a person at heights above ground level, and enabling said 
person to remove and reengage the attachment to different rungs of the 
ladder if needed to perform the desired work activity. 
These, together with other objects and advantages of the invention, reside 
in the details of the process and the operation thereof, as is more fully 
hereinafter described and claimed. References are made to drawings forming 
a part hereof, wherein like numerals refer to like parts throughout.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) OF THE INVENTION 
Referring now to the drawings, there is shown in FIG. 1 the locking safety 
platform secured to two rungs of a ladder 90, said rungs are upper rung 92 
and lower rung 94. Foot platform 10 is supported on lower rung 94 in a 
horizontal position. 
As shown in FIG. 2, platform 10 has stop 20 on the bottom thereof to 
prevent forward movement when weight is applied to the platform; the force 
of gravity causes stop 20 into engagement with the lower rung 94. Support 
brackets 12 are attached to the rear of the said platform 10 at the sides 
thereof and extend at an acute angle to the proximate front midpoint of 
the next higher rung of the ladder, the upper rung 92. A horizontal 
cross-brace 14 connects the support brackets at the proximate midpoints 
thereof. Support brackets 12 terminate in a horizontal plane at hinge 
member 16. 
FIG. 3 shows arcuate support members 40 attached to said hinged members 16 
for engagement with the upper rung 92 of ladder 90. Each of the arcuate 
support members 40 terminate in a vertical leg 42. 
As shown in FIG. 4, a cross-member 44 is attached to the vertical legs 42 
so that the hinge members 16 operate together. A securing or locking arm 
46 is attached by pivoting means 30, such as a nut and bolt assembly, at 
the midpoint of said cross-member 44, for engagement with the front of the 
cross-brace 14 connecting the support brackets 12 and forming locking 
means 47. The locking arm 46 has rearward spring action so that force is 
required to move it forward to clear the cross-brace 14 before the locking 
arm 46 can be moved into a vertical position for engagement with the 
cross-brace 14. Knob 48 is attached near the proximate end of locking arm 
46 to provide easy gripping means for the user in moving locking arm 46 
from the release position, 46a to the locked position, indicated by 
central axis 46b. In securing locking means 47 in such a manner, the 
ladder safety platform is in a fixed, stable position, and said foot 
platform 10 is at a generally horizontal plane. 
In operation, the user would climb ladder 90 to a height a few rungs below 
the desired height required to perform the intended work activity. The 
ladder safety platform, which can be fabricated of metal or other rigid, 
weight bearing, durable material, including plastic, can be easily carried 
by the user up the ladder by means of knob 48 or cross-brace 14. 
The user then places the invention on the upper and lower rungs as 
previously described in a fixed position. No tools or complicated 
mechanical measures are required for this procedure. The user then places 
articles, such as tools or paint containers, on foot platform 10 for use 
in the work activity, or uses the platform 10 to stand upon for 
performance of the work activity. Platform 10 can have a smooth surface, 
or, if desired, a rough surface to provide more friction between the 
user's foot 96 and platform 10, so as to prevent the user from slipping 
therefrom. Hinge members 16 and/or support brackets 12 can be padded so as 
to prevent injury to the user's leg or damage to the user's clothing from 
contact with the invention. 
Once the user has completed the work activity, he can reverse the 
above-described procedure to disengage the safety platform and either 
ascend or descend the ladder 90 to a different position on said ladder. At 
this height the user can engage the platform for work activity at this 
height above ground level. Or the user can disengage the safety platform 
and descend to ground level. 
The foregoing is considered as illustrative only of the principles of the 
invention. Further, since numerous modifications and changes will readily 
occur to those skilled in the art, it is not desired to limit the 
invention to the exact construction and operation shown and described, and 
accordingly, all suitable modifications, and equivalents which may be 
resorted to, fall within the scope of the invention.