Safety ladder with caster assembly moveable positively to a retracted position

Claim 2

A ladder assembly comprising a frame, a plurality of steps and at least three support feet for supporting said ladder assembly on a generally horizontal surface, said ladder assembly including a caster assembly upon which the ladder is adapted to be rollingly transported from one location to another, said caster assembly including at least three casters which are positively and conjointly movable between a first retracted position in which said support feet stably support said ladder assembly on said horizontal surface with said casters elevated thereabove and a second transporting position in which said casters stably support said ladder assembly on said horizontal surface with said support feet elevated thereabove, tubular guide means fixedly secured to said ladder assembly reciprocatably mounting said casters for reciprocating movement between said first and second positions, spring means urging said casters into said first retracted position, linkage means interconnecting said casters for conjoint movement, and actuating means for operating said linkage means to move said casters from said first to said second position.

Claim 3

A ladder assembly in accordance with claim 1 wherein said actuating means comprises a foot pedal fixed to said linkage means.

Claim 4

A ladder assembly comprising a frame, a plurality of steps and at least three support feet for supporting said ladder assembly on a generally horizontal surface, said ladder assembly including a caster assembly upon which the ladder is adapted to be rollingly transported from one location to another, said caster assembly including at least three casters which are positively and conjointly movable between a first retracted position in which said support feet stably support said ladder assembly on said horizontal surface and a second transporting position in which said casters stably support said ladder assembly on said horizontal surface with said support feet elevated thereabove, tubular guide means fixedly secured to said ladder assembly reciprocatably mounting said casters for reciprocating movement between said first and second positions, spring means urging said casters into said first retracted position, linkage means interconnecting said casters for conjoint movement, and actuating means for operating said linkage means to move said casters from said first to said second position, said linkage means comprising lever means mounted for oscillation between a rest position in which said casters are retracted towards said second transporting portion against the force of said spring means and an over-center position in which said casters are releasably locked in said transporting position.

Claim 5

A ladder assembly comprising a frame, a plurality of steps and at least three support feet for supporting said ladder assembly on a generally horizontal surface, said ladder assembly including a caster assembly upon which the ladder is adapted to be rollingly transported from one location to another, said caster assembly including at least three casters which are positively and conjointly movable between a first retracted position in which said support feet stably support said ladder assembly on said horizontal surface and a second transporting position in which said casters stably support said ladder assembly on said horizontal surface with said support feet elevated thereabove, tubular guide means fixedly secured to said ladder assembly reciprocatably mounting said casters for reciprocating movement between said first and second positions, spring means urging said casters into said first retracted position, linkage means interconnecting said casters for conjoint movement, and actuating means for operating said linkage means to move said casters from said first to said second position, said linkage means comprising lever means mounted for oscillation between a rest position in which said casters are retracted towards said second transporting portion against the force of said spring means and an over-center position in which said casters are releasably locked in said transporting position.

Claim 6

A ladder assembly in accordance with claim 3 in which said lever means comprises a pivotally interconnected crank bar and cam lever oscillatably mounted respectively on said caster mounting means and said caster.

Claim 7

A ladder assembly in accordance with claim 3 further comprising retracting means for engaging said linkage means for returning said lever means from said over-center position toward said rest position.

Claim 8

A ladder assembly comprising a frame, a plurality of steps and at least three support feet for supporting said ladder assembly on a generally horizontal surface, said ladder assembly including a caster assembly upon which the ladder is adapted to be rollingly transported from one location to another, said caster assembly including at least three casters which are positively and conjointly movable between a first retracted position in which said support feet stably support said ladder assembly on said horizontal surface with said casters elevated thereabove and a second transporting position in which said casters stably support said ladder assembly on said horizontal surface with said support feet elevated thereabove, caster support members, each of which supports one of said casters mounted thereon wherein said casters are mounted for reciprocating conjoint movement between said first and second positions, a tubular member slidably receiving a caster support member, spring means connected to said tubular member and caster support member for biasing said casters toward said retracted position, linkage means interconnecting said casters for conjoint movement, and actuating means for operating said linkage means to move said casters from said first to said second position.

Claim 9

A ladder assembly comprising a frame, a plurality of steps and at least three support feet for supporting said ladder assembly on a generally horizontal surface, said ladder assembly including a caster assembly upon which the ladder is adapted to be rollingly transported from one location to another, said caster assembly including at least three casters which are positively and conjointly movable between a first retracted position in which said support feet stably support said ladder assembly on said horizontal surface with said casters elevated thereabove and a second transporting position in which said casters stably support said ladder assembly on said horizontal surface with said support feet elevated thereabove, caster support members, each of which supports one of said casters mounted thereon wherein said casters are mounted for reciprocating conjoint movement between said first and second positions, a tubular member slidably receiving a caster support member, spring means connected to said tubular member and caster support member for biasing said casters toward said retracted position, linkage means interconnecting said casters for conjoint movement, and actuating means for operating said linkage means to move said casters from said first to said second position.

Claim 10

A ladder assembly in accordance with claim 6 wherein said linkage means includes lever means operative to act against said spring means and moveable between a rest position and an over-center position corresponding to said retracted and transporting positions respectively, and in which over-center position said caster support members and casters are releasably locked, and from which position said caster support members and casters are adapted to be returned by said springs to said rest positions.

Claim 11

A ladder assembly in accordance with claim 7 further comprising retracting means for returning said casters to said retracted position.

Claim 12

A ladder assembly in accordance with claim 8 in which said retracting means comprise a retracting pedal mounted on said ladder assembly, said retracting pedal comprising an arm positioned to engage and to move said lever means from said over-center position.