Title:
REMOVABLE LADDER APRON CONSTRUCTION
United States Patent 3812932
Abstract:
A removably mounted apron for a collapsible type wooden ladder adapted to slideably receive the supporting bars of a conventional apron in moderate frictional gripping relationship. The removable apron includes sidewalls provided with a gradual taper which defines the limit of inward travel of the apron upon the supporting bars and which provide the means for frictional gripping of the support arms.
Application Number:
05/371403
Publication Date:
05/28/1974
International Classes:
E06C7/16; E06C7/00; (IPC1-7): E06C7/14
Field of Search:
182/126,125,228,230,124 248
Primary Examiner:
Machado, Reinaldo P.
Attorney, Agent or Firm:
Cennamo, Kremblas & Foster
Claims:
What is claimed is
1. A removable apron for repair of a foldable type ladder provided with a pair of laterally spaced pivotable support arms comprising a generally flat shelf portion provided with turned down lateral edge portions defining horizontally spaced walls, said lateral edges defining a gentle taper from the rearward edge to the forward edge of said shelf and adapted to slideably and removably receive said support arms in frictional gripping relationship with the shelf portion being supported in a stable position upon said arms.
2. A removable apron for a foldable type ladder provided with a pair of laterally spaced, generally co-planar support arms pivotably mounted on the ladder, comprising a generally flat shelf portion provided with turned under lateral edges defining a pair of channels, said lateral edges defining a tapered configuration such that said channels converge toward one another from the rear edge toward the forward edge of said shelf portion, and wherein said channels are adapted to slideably receive said support arms of said ladder in increasing frictional engagement as the channels are progressively received by said arms.
3. The apron defined in claim 1 wherein said shelf portion defines a continuous surface between said lateral edges.
4. The apron defined in claim 2 wherein said channels are adapted to removably receive said support arms with said shelf portion defining a generally co-planar surface with the bottom surface of said support arms and wherein said channels cooperate with said arms to define side rails extending the length of said shelf portion.
5. An improved foldable ladder assembly having two pair of legs hingedly connected near the top of said ladder and a pair of laterally spaced, generally co-planar support arms, a respective one of said arms being pivoted to a respective one of a pair of said legs, the improvement comprising a relatively rigid apron portion of durable sheet material removably mounted upon said support arms to define a pivotable platform, said apron including turned down lateral edge portions, said portions including a wall defining a taper adapted to removably receive said support arms in increasing frictional gripping relationship with progressive movement of said shelf upon said arms.
6. The ladder assembly defined in claim 5 wherein each of said turned down lateral edges define at least two side walls which with said shelf portion define a channel and wherein said channels are adapted to optionally receive said support arms in a stable frictionally gripping relationship with said defined platform being generally co-planar with the bottom surface of said arms and with said channels cooperating with said arms to form longitudinally extending rails raised above the surface of said platform portion.
Description:
BACKGROUND
Wooden ladders of the foldable or collapsible type and provided with a pivotable apron having been known and widely used for many decades. Generally speaking, this type of ladder possesses a relatively long life and is much less expensive than aluminum or other metal type ladders. Most homeowners own such a ladder and professional painters make great use of such ladders for indoor painting as well as for some types of outdoor painting.
One of the primary problems with such ladders is that the pivotable wooden shelf or apron, which generally comprises a few individual thin boards nailed upon a pair of pivotably mounted support arms, is easily broken. This represents a very high source of irritation as the apron usually becomes broken in a very short time compared to the useful life of the main ladder assembly. This problem is particularly aggravating in the case of professional painters as they subject such ladders to heavy and constant use. But it is also an aggravating and frustating problem to the many consumers who buy and use such ladders.
SUMMARY OF INVENTION
the present invention relates generally to ladder accessories and particularly to a novel apron or shelf adapted to be removably mounted on the support arms for the pivotable shelf of a conventional foldable ladder. The removable apron is preferably made of metal or a very durable plastic material and includes a pair of channels or guides which slideably receive the support arms of the ladder to provide a durable, long lasting apron. It may be used to simply and easily repair a used ladder or it can be installed on a new ladder if desired.
OBJECTS
It is a primary object of the present invention to provide a removable ladder apron which can be quickly and simply mounted on a foldable type ladder to provide a strong, durable ladder shelf for used or new ladders.
It is another object of the present invention to provide a ladder apron of the type described which includes features which assure proper placement of the apron to remain in this stable position during subsequent use.
It is a further object of the present invention to provide a removable apron of the type described which is more durable than the present original apron construction provided with this type of ladder and which is constructed to fit the support arms of ladders within a relatively wide tolerance of the same nominal size.
IN THE DRAWINGS
FIG. 1 is a perspective view of a typical foldable type ladder illustrated with a removably mounted apron constructed in accordance with the present invention mounted thereon;
FIG. 2 is a partial perspective view of the ladder assembly shown in FIG. 1 illustrating the slideably mounted relationship between the pivotable support arms and the apron of the present invention;
FIG. 2A is a partial perspective view of the ladder assembly shown in FIG. 1 illustrating the apron mounted in a modified position as compared to the position shown in FIG. 2;
FIG. 3 is a side elevational view of the apron illustrated in FIG. 1 shown removed from the ladder;
FIG. 3A is a side elevational view of a modified embodiment of the present invention;
FIG. 4 is a front elevational view of the apron shown in FIG. 3;
FIG. 4A is a front elevational view of the modified embodiment shown in FIG. 3A; and
FIG. 5 is a top plan view of the apron shown in FIG. 3.
DETAILED DESCRIPTION
Referring in detail to drawings, a conventional type of foldable ladder, indicated generally at 20 which includes the pivotal support arms 22 conventionally associated with a fold-away permanent shelf or apron, is shown in FIG. 1. Ladder 20 typically includes two pair of legs 24 and 26 hingedly connected to a top step 28 to permit the assembly to be folded for convenient storage.
Each support arm 22 is conventionally pivoted to a respective one of the pair of legs 24 and the outer end portions are prevented from pivoting downwardly past the horizontal by the contact of the inner end portions of arms 22 with the next highest step 30. However, the arms may be pivoted in the reverse direction to a vertical position when not in use or when the ladder is disposed in its folded position.
The apron, indicated generally at 32 of the present invention includes a generally flat shelf portion 34 and integrally formed channels 36 forming guide and attaching means which extend along the outer edges.
Channel portions 36 coincide with the outer edges of shelf portion 34 to define a gentle tapered configuration from the rear 40 toward the front edge 38.
Channel portions 36 are adapted to slideably and removably receive the outer ends of support arms 22 as shown in FIG. 2. As the channel portions are pushed farther onto the arms 22, frictional engagement is achieved to secure the apron 22 in proper position on the arms. Preferably the degree of taper of the channel portions 36 is gradual to permit the apron to extend almost fully upon the support arms with only moderate pressure being necessary toward the last few inches of travel. Further, the width of the channel portions 36 is preferably designed to be sufficient to permit a relatively loose fit as determined by the average width of an individual support arm for conventional ladders of a given nominal size.
This feature serves multiple purposes. First, this design will enable the user to more easily initially position the channels upon the arms and slide the apron into position. Second, the loose fit will permit the same apron to be used on most ladders of different manufacturers within a greater size differential of the support arm 22.
And thirdly, the loose fit described in conjunction with the appropriate taper of the outer edges of shelf 34 which defines the angle of convergence of channels 36, cooperate together to serve the versatility and ease of use mentioned above without diminishing the ability to snuggly position the apron 32 upon the support arms 22. The limiting factor to attain the required frictional engagement for stability being the distance defined between the outer sidewalls or arms 22 and their relationship to the width between the inner walls of channels 36. In addition, the frictional engagement of the channels 36 and arms 22 over a moderate portion of their length serves to make the arms 22 more stable and rigid since the apron is relatively rigid and has greater strength as compared to the wooden frame.
Most of these same advantages can be achieved by an alternative construction as shown in FIGS. 3A and 4A. In this modified embodiment, the depth of the channel 36A is tapered from the rear toward the front edge of shelf 34A. In this manner a similar frictional engagement is achieved as the channels are slideably moved over the support arms. A similar result could be achieved by providing a taper in the width of the channels.
However, it should be pointed out, that the construction shown in the embodiment of FIG. 3-5 appears to be preferred as the most simple and the least expensive to manufacture and fabricate.
Now specifically referring to FIG. 2A, a modified embodiment and method of use is shown illustrating other advantages of the present invention as compared with the prior art structure.
As seen in FIG. 2A, apron 32 is removably mounted in reverse configuration as compared to FIG. 1. The advantages and conveniences described above are retained, but a further advantage is achieved in that channels 36 now define, in effect, side rails which offer protection against inadvertent spilling of a container placed upon the apron 32.
As has been experienced by most persons who have used such ladders for painting or washing walls or the like, in one fashion or another, the container has inadvertently fallen off the apron or has been tipped over to spill the contents. The frustation and irritation of the user in such situations is well-known. The apron of the present invention used in the configuration shown in FIG. 2A defines a ladder apron configuration which offers at least some significant protection against such occurrences which has not been offered by prior art constructions.
It should be readily apparent from the foregoing description that the apron of the present invention offers a solution to a problem long recognized, but heretofore unsolved. Further, it offers advantages not offered by the shelf provided on a new ladder. It should be pointed out that while the apron is most likely to be used to repair or renovate a used ladder having a broken original permanent shelf, there are sufficient advantages to justify mounting the apron on a newly purchased ladder over the original shelf. This would be possible in most present ladder constructions since the original shelf usually consists of boards which are sufficiently thin that they would not offer a problem in fitting the apron 32 over the arms 22. Of course, the original shelf could be removed if it did offer difficulty in mounting of the apron 32.