Claims
- 1. A plastic ladder comprising:
- a first plastic side rail, at least a portion of which is hollow;
- a second plastic side rail, at least a portion of which is hollow, said second side rail in parallel with the first side rail;
- a plurality of steps, each of which is attached to the first and second rails at predetermined locations such that each step forms a flat weight bearing platform upon which a user can stand; and
- wherein the first and second rails each have a plurality of pockets having solid cross sections disposed therealong at predetermined positions, and each of said steps are attached to the first and second rails at corresponding pockets therein with fasteners through holes in the solid cross sections.
- 2. A plastic ladder as described in claim 1 wherein the solid cross sections are of a greater thickness than solid portions of cross sections of the first and second rails at other than the predetermined positions.
- 3. A plastic ladder as described in claim 2 wherein the first and second rails and the steps define a front section; and
- including a third side rail and a fourth side rail disposed essentially in parallel with the third side rail;
- a plurality of bracing elements, each of which are attached to the third and fourth side rails to support the third and fourth side rails, said third and fourth side rails and said bracing elements define a rear section; and
- a top which is connected to the front and rear sections at the top ends of the first and second rails, and the top ends of the third and fourth rails such that the front and rear sections form a v-shape when deployed and fold on top of each other when undeployed.
- 4. A plastic ladder as described in claim 3 wherein the ends of the first and second side rails are fixedly connected to the top, and the ends of the third and fourth side rails are rotatably connected to the top.
- 5. A plastic ladder as described in claim 4 including a first linkage and a second linkage connecting the first and third side rails, and second and fourth side rails, respectively, such that when the front and rear sections are deployed, the linkages securely maintain the v-shape that is formed thereby; and when the front and rear sections are undeployed, the linkages fold.
- 6. A plastic ladder as described in claim 5 wherein each side rail has a cross section which is essentially in the shape of a C.
- 7. A plastic ladder as described in claim 6 wherein the top, the third and fourth side rails, and the bracing elements are made of plastic.
- 8. A plastic ladder as described in claim 7 wherein the top, the first, second, third and fourth side rails, and the bracing elements are blow molded.
Parent Case Info
This is a continuation of copending application Ser. No. 07/565,966 filed Aug. 10, 1990; now U.S. Pat No. 5,131,495.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
Country |
Parent |
565966 |
Aug 1990 |
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