This invention relates to stepladder structure to improve ladder lateral stability and provide utility devices adjacent the top of the ladder. The new ladder structure includes four deployable lateral support legs and at least one utility support tray attached adjacent the top of the ladder.
The concept of increasing a stepladder total width at the base of the ladder may be known. There are various issued patents that disclose and discuss that this feature has been established as an important element for ladder stability. Likewise there are a variety of disclosures and issued patents with lateral stability elements. However, the various advancements in this field of the art still show there is a need for improvement of the structure of a stepladder for stability that may be a combination of ladder strength as well as the structure of deployable lateral support legs, width of ladder rungs and availability of utility support trays. A properly structured ladder may allow use of existing ladder transport equipment, storage facilities, shipping space and other ladder accessories.
The present invention is directed to stepladders that are structured to provide improved lateral stability, step support and equipment/supplies support for stepladder users. The stepladder may have a step element and a support element rotatably attached at a top platform or a first step element rotatably attached to a second step element adjacent a top step. A hinged strut may be attached at opposed ends between the opposed elements intermediate the ladder top and the ladder base. A plurality of steps may be spaced apart and attached between step rails of step elements. A lateral support leg may be rotatably attached at a top end to each of the step rails intermediate a second step and a third step from the ladder top and a hinged leg strut may be attached at opposed ends between each of the support rails and lateral support legs.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
The following detailed description represents the best currently contemplated modes for carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention.
Referring to
The support rails 24 may have horizontal support members 28 attached between the two support rails 24 spaced apart a distance selected for structural support of the ladder 10. Angular braces 42 may be attached between one or more of the steps 26 and the step rails 22 and between the support members 28 and the support rails 24 to strengthen the ladder 10. The angular braces 42 may be attached in pairs at each side wall 44 of the rails 22, 24 and steps 26 or support member 28.
Deployable lateral support legs 50 may be rotatably attached at a top end 52 by a rotatable fastener 112 to each of the step rails 22 and lateral legs 51 may be attached at a top end 49 by a fastener 112 to each of the support rails 24. A hinged strut leg 37 may be attached at opposed ends 38 between each of a step rail 22, or a support rail 24 and a lateral support leg 50 or a lateral leg 51. When a leg 50 is deployed the hinged leg strut 37 may support the foot 54 or bottom end of the leg 50 a predetermined distance from the bottom end 40 of a rail 22, 24. The legs 50 may be structured as “U” shape or open channel beams with side walls 56 spaced apart sufficiently to allow the legs 50 when moved against a rail 22, 24 to overlap the rail 22, 24 with the side walls 56 positioned on the rail 22, 24 side walls 44. When the legs 50 are in the stowed position the ladder 10 step and support members 20, 30 may present a narrow profile similar to standard stepladders. The stepladder 10 with stowed legs 50 may be stored, transported and shipped using existing stepladder handling equipment.
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The legs 50 may be attached intermediate the second and third step of the step element 20 to allow optimal stability support for the stepladder 10 when the legs 50 may be deployed. General practice for safe use of a stepladder may be to not climb the ladder higher than the second or third step from the top platform 32. Experiments with stepladders 10 have demonstrated that a reasonable separation distance between the step rail 22 bottom end 40 and the leg 50 foot 54 for ladder stability may be to approximately double the width of the base 34. An equivalent attachment distance from the top 32 and for the separation distance between the bottom end 40 and foot 54 for the support rails 24 when used with legs 50 also may improve ladder 10 stability.
For additional safe use of the stepladder 10, utility trays 60 may be attached adjacent to the top platform 32 in position to hold tools, supplies, paint and the like for ease of access to a user of the stepladder 10. Trays 60 may be attached by slidable engagement of one or more slots 64 formed in a side 66 of the tray 60 with capped lugs 62 that are attached to the upper portion of the rails 22, 24. The tray 60 may have four sides 66 that may be 2 inches high to retain elements in the tray 60. The tray 60 may also be structured as a paint tray to hold paint for a user to apply paint to a paint roller (not shown). The tray 60 may have a width to extend outwardly from a side of the ladder 10 a distance approximately equal to the deployed distance between a bottom end 40 and foot 54 to allow placement of a ladder 10 abut a vertical structure.
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Evaluation of the stepladder 10 structure, particularly the dual step element ladder 20A, 20B, by medical professionals found that the generally rigid structure with the long support legs 50 and the wide steps 26 allowed better balance with less stress to the entire muscular-skeletal system. Unnecessary stress applied to the body can in turn cause conditions such as neck pain, upper back pain, pain across the shoulders, middle back pain, lower back pain, hip pain, knee pain and foot/ankle pain. The added stress and strains can also cause the body to fatigue more quickly, which in turn can lead to both physical and mental fatigue and impairment. The stability elements in the structure of the stepladder 10 should reduce these stress issues and the chance of injury for ladder users.
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While the invention has been particularly shown and described with respect to the illustrated embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
This is a continuation-in-part patent application of U.S. patent application Ser. No. 12/806,080, filed on Aug. 5, 2010. U.S. patent application Ser. No. 12/806,080 is pending
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Number | Date | Country | |
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Parent | 12806080 | Aug 2010 | US |
Child | 13134710 | US |