In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.
Referring to the drawings, the attachment 10 includes a one piece elongated member 12 preferably molded from a moldable material such as hard rubber, plastic or an elastomer material such as urethane, silicone, PVC or similar polmeric resins. Hard rubber or urethane are preferred materials Other material can be used such as wood, metal, etc., but this may require more costly forming or machining steps.
The member 12 is generally elongated and stiff to not be easily bent so as to resist excessive deflection when loaded as by the weight of a person on the ladder with the member supporting the upper end of the ladder leaning against a support. The member 12 is formed with an arcuate cavity 14 recessed into one side of the member 12 with a pair of integral end parts 16 located on either side of the cavity 14. The cavity 14 is sized to be approximately matched to the outer contour of utility poles, tree trunks, etc., i.e., an approximate radius on the order of 15 inches.
A series of vertical steps 18 line the interior of the cavity 14 in the outer regions thereof to create frictional gripping features. The cavity 14 including the steps 18 can be tapered out from top to bottom to better match the slope of a leaned ladder when in a correctly angled position against a utility pole P, or tree trunk T as seen in
A pair of arcuate slits 20 extend into the one side of the member 12 and closely spaced out from the outer surface of the cavity 14 and follow its contour to form a pair of opposed curved gripper wing portions 22 integral at one end with the member 12 and concentric to a respective side of the cavity 14. This allows inward movement of each gripper wing portion 22 towards each other by resilient bending of a material at the end of the slits 20. Further bending of the curved wing portions 22 along their lengths allows the achievement of better conformity with the exterior of a utility pole P (
The gripper wing portions 22 are moved towards each other by means of an encircling strap 26 which also holds the wing gripper portions 22 in position when the ends are connected.
Each end part 16 is formed with a rectangular hole 24 extending crosswise to the length of the member 12 (generally vertically), which holes 24 are sized and spaced apart so as to be able to receive the upper ends of the stiles 28 of a lean ladder 30 (
The strap 26 is held on the member 12 by being passed through the slits 20 (a recess 27 accommodating the strap 26) and out through slots 34 and around the rear of the member 12 (
The end parts 16 are each formed with chamfered corners 36 and lightening holes 38 to save weight and material. The holes 38 can also serve as holding receptacles as for tools T, and smaller holes 40, 42 can also be provided for this same purpose. Holes 48 for paint can hooks 45 can also be provided as seen in
Ridges 50 on the flat outer faces 52 of the end parts 16 increase friction when the ladder 30 is propped against a flat wall (not shown).
The surfaces 52 are located outboard from the ladder stiles 28 and greatly increase frictional engagement with a flat surface to improve stability of the ladder when leaned against a flat surface, resisting sliding, tipping or twisting of the ladder.
The ladder attachment according to the invention has many advantages over the prior devices:
The simple one piece molded member reduces the cost of manufacture.
It also allows for safe use of trees, poles and small diameter pilings as a ladder support.
The preferred elastomeric material also eliminates scratches on support surfaces which the ladder is leaning against such as the paint of aluminum siding or on a transporting vehicle.
The attachment 10 stabilizes a ladder from side to side, even when used against uneven objects or surfaces by the outboard, widely spaced location of the end parts 16.
The ribbed surface 50 allows increased friction against flat support surfaces.
The elastomeric material won't damage trees and allows tightening to grip a pole or tree tightly.
The preferred elastomer material is electrically insulating to prevent electrical shock when contacting a live conductor.