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US 7,108,103 B2Granted
Rigidified step ladder
AssigneeCosco Management, Inc.
InventorPaul K. Meeker
Life of this patent
Estimating the term…
Abstract
A step ladder includes rigidified left and right legs and step units between the legs. Each rigidified leg includes a web interconnecting first and second tubular members. Each step unit includes a hollow step including an internal rigidifying partition wall and step mounts for coupling the hollow step to the legs.
Claims17
A step ladder comprising
- a frame including a left leg and a right leg, each of the left and right legs including spaced-apart first and second tubular members and a web located between and coupled to the first and second tubular members, and
- a plurality of step units arranged to lie between the left and right legs, each step unit being coupled to the left and right legs to support said step unit in a stationary position relative to the left and right legs, wherein each of the first and second tubular members of the left leg includes first, second, third, and fourth side walls arranged in series to define an interior region therebetween and wherein the first side walls of said first and second tubular members lie in coextensive relation with a first reference plane, the second side walls of the said first and second tubular members are coupled to the web located between the first and second tubular members, and the third side walls of said first and second tubular members lie in coextensive relation with a second reference plane that is oriented to cooperate with the first reference plane to define a first acute included angle therebetween.
A step ladder comprising
- a front frame portion including a left leg and a right leg, each of the left and right legs of the front frame portion including first and second tubular members and a front web located between and coupled to each of the first and second tubular members,
- a rear frame portion mounted for movement relative to the front frame portion between an expanded position supporting the front frame portion in an inclined position and a collapsed position lying alongside the front frame portion, the rear frame portion including a left leg pivotably coupled to the left leg of the front frame portion and a right leg pivotably coupled to the right leg of the front frame portion, each of the left and right legs of the rear frame portion including third and fourth tubular members and a rear web located between and coupled to each of the third and fourth tubular members, and
- a plurality of step units arranged to lie between the left and right legs of the front frame portion, each step unit being coupled to the left and right legs of the front frame portion to support said step unit in a fixed position relative to the left and right legs of the front frame portion, wherein each of the first, second, third, and fourth tubular members of the left legs of the front and rear frame portions include first, second, third, and fourth side walls arranged in series to define an interior region therebetween and wherein the first side walls of said first, second, third, and fourth tubular members lie in coextensive relation with a first reference plane, the second side walls of said first and second tubular members are coupled to the front web, the second side walls of said third and fourth tubular members are coupled to the rear web, the third side walls of said first and second tubular members lie in coextensive relation with a second reference plane that is oriented to cooperate with the first reference plane to define a first acute included angle therebetween, the third side walls of said third and fourth tubular members lie in coextensive relation with a fifth reference plane that is oriented to cooperate with the first reference plane to define a third acute included angle therebetween and to cooperate with the second reference plane to define an obtuse included angle therebetween.
Dependencies are inferred from the claim text.