Ladder system for installation in manholes

Claim 2

A ladder system for installation in a generally vertically disposed passageway defined by a plurality of casing sections which can be mated together in a stacked relationship, comprising the combination of: individual ladder sections which can be secured to the casing section to form a ladder system within the passageway defined by said casing sections, each of said ladder sections having anchoring means at an upper end for hanging the ladder section from the upper edge of a casing section said anchoring means comprising a pair of horizontally disposed extensions of vertical legs of a ladder section, with a further horizontally disposed element interconnecting the terminal ends of the horizontally disposed extensions, individual casing sections which include upper and lower ends that can be mated with one another in stacked relationships to form a continuous casing assembly defining a generally vertically disposed passageway, and including in the casing assembly individual casing sections having recess means formed in one of their ends for receiving the anchoring means of individual ladder sections, said recess means being formed into the individual casing sections so as to communicate with the interior space of the casing assembly without penetrating through to the exterior of the casing assembly at any point.

Claim 3

The ladder system of claim 1 and including sealing means for sealing the mated casing sections relative to one another.

Claim 4

The ladder system of claim 1 wherein each ladder section includes attaching means at its lower end for attaching the ladder section to a next lower ladder section in an assembly of such ladder sections in a casing.

Claim 5

The ladder system of claim 3 wherein said attaching means of each ladder section includes at least one downwardly depending element which can be engaged with a portion of a next lower ladder section.

Claim 6

The ladder system of claim 1 wherein each ladder section includes a pair of spaced legs with rungs interconnected therebetween, means for spacing the spaced legs away frOm the interior wall of a casing in which the ladder section is installed, and attaching means at a lower end of each section for securing the ladder section to a next lower ladder section in an assembly of such ladder sections in a casing.

Claim 7

The ladder system of claim 5 wherein said attaching means comprises at least one downwardly depending element extending below the lower end of the ladder section for being engaged by a portion of a next lower ladder section in an assembly of such sections.

Claim 8

The ladder system of claim 6 wherein said downwardly depending element is positioned to be in close proximity to, or in contact with, the interior wall of a casing assembly when the ladder assembly is installed within the casing assembly.

Claim 9

The ladder system of claim 7 wherein said downwardly depending element is engaged by a horizontally disposed element carried by an upper end portion of a next lower ladder section, said horizontally disposed element being generally parallel to the rungs of the ladder and positioned to interconnect a pair of horizontally disposed extensions of the legs of the ladder.

Claim 10

The ladder system of claim 1 wherein said recess means of each casing section comprises a continuous recess formed into the upper end of each casing section so as to permit placement of a ladder section and its anchoring means at any position about the circumference of the casing section.

Claim 11

The ladder system of claim 1 wherein said recess means of each casing section is formed into a ledge portion defined at the upper end of the casing section so that portions of a ladder section can rest on the ledge when installed in the casing section with the anchoring means received into the recess means.

Claim 12

The ladder system of claim 10 wherein said recess means comprises a continuous groove.

Claim 13

The ladder system of claim 10 wherein said recess means comprises discrete formations for receiving the anchoring means of a ladder section in mating relationship.

Claim 14

The ladder system of claim 10 wherein the lower end of each casing section is shaped to mate with the ledge portion formed at the upper end of a next adjacent lower casing section in an assembly of such casing sections.

Claim 15

The ladder system of claim 13 wherein the lower end of each casing section includes recesses for straddling a ladder section installed on a next adjacent lower casing section.

Claim 16

The ladder system of claim 14 wherein said anchoring means comprises a horizontally disposed element which interconnects the terminal ends of said horizontally disposed extensions of each ladder section.

Claim 17

A ladder system for installation in a generally vertically disposed passageway defined by a plurality of casing sections which can be mated together in a stacked relationship, comprising the combination of: individual ladder sections which can be secured to the casing section to form a ladder system within the passageway defined by said casing sections, each of said ladder sections having anchoring means at an upper end for hanging the ladder section from the upper edge of a casing section, and each of said ladder sections further having an attaching means at its lower end for attaching the ladder section to a next lower ladder section in an assembly of such ladder sections in a casing, said attaching means including at least one downwardly depending element which can be engaged with a portion of a next lower ladder section, individual casing sections which include upper and lower ends that can be mated with one another in stacked relationships to form a continuous casing assembly defining a generally vertically disposed passageway, and including in the casing assembly individual casing sections having recess means formed in one of their ends for receiving the anchoring means of individual ladder sections, said recess means being formed into the individual casing sections so as to communicate with the interior space of the casing assembly without penetrating through to the exterior of the casing assembly at any point. 17. A ladder system for installation in a generally vertically disposed passageway defined by a plurality of casing sections which can be mated together in a stacked relationship, comprising the combination of: individual ladder sections which can be secured to the casing section to form a ladder system within the passageway defined by said casing sections, each ladder section including a pair of vertical legs spaced apart with ladder rungs interconnected therebetween, and with a horizontally disposed extension at the upper end of each vertical leg, and each of said ladder sections having anchoring means secured to said horizontally disposed extensions for hanging the ladder section from the upper edge of a casing section, said anchor means comprising horizontally disposed elements connected at angles to each of said horizontally disposed extensions, individual casing sections which include upper and lower ends that can be mated with one another in stacked relationships to form a continuous casing assembly defining a generally vertically disposed passageway, and including in the casing assembly individual casing sections having recess means formed in one of their ends for receiving the anchoring means of individual ladder sections, said recess means being formed into the individual casing sections so as to communicate with the interior space of the casing assembly without penetrating through to the exterior of the casing assembly at any point.

Claim 18

A ladder system for installation in a generally vertically disposed passageway defined by a plurality of casing sections which can be mated together in a stacked relationship, comprising the combination of: individual ladder sections which can be secured to the casing section to form a ladder system within the passageway defined by said casing sections, each of said ladder sections having anchoring means at an upper end for hanging the ladder section from the upper edge of a casing section, and each of said ladder sections further having an attaching means at its lower end for attaching the ladder section to a next lower ladder section in an assembly of such ladder sections in a casing, said attaching means including at least one downwardly depending element which can be engaged with a portion of a next lower ladder section, individual casing sections which include upper and lower ends that can be mated with one another in stacked relationships to form a continuous casing assembly defining a generally vertically disposed passageway, and including in the casing assembly individual casing sections having recess means formed in one of their ends for receiving the anchoring means of individual ladder sections, said recess means being formed into the individual casing sections so as to communicate with the interior space of the casing assembly without penetrating through to the exterior of the casing assembly at any point. 17. A ladder system for installation in a generally vertically disposed passageway defined by a plurality of casing sections which can be mated together in a stacked relationship, comprising the combination of: individual ladder sections which can be secured to the casing section to form a ladder system within the passageway defined by said casing sections, each ladder section including a pair of vertical legs spaced apart with ladder rungs interconnected therebetween, and with a horizontally disposed extension at the upper end of each vertical leg, and each of said ladder sections having anchoring means secured to said horizontally disposed extensions for hanging the ladder section from the upper edge of a casing section, said anchor means comprising horizontally disposed elements connected at angles to each of said horizontally disposed extensions, individual casing sections which include upper and lower ends that can be mated with one another in stacked relationships to form a continuous casing assembly defining a generally vertically disposed passageway, and including in the casing assembly individual casing sections having recess means formed in one of their ends for receiving the anchoring means of individual ladder sections, said recess means being formed into the individual casing sections so as to communicate with the interior space of the casing assembly without penetrating through to the exterior of the casing assembly at any point.