Work Platform for Construction of Pipelines

Abstract

A work platform configured to mount on top of a manhole casing comprising a cylindrical casing exterior surface and a central bore having a cylindrical bore interior surface can comprise a deck/frame structure and a cylindrical interlock lip secured thereto. The interlock lip includes a cylindrical lip interior surface and a cylindrical lip exterior surface and can be sized and shaped to either nest into the central bore with the lip exterior surface extending parallel and closely adjacent to the bore interior surface or to fit snugly around the manhole casing with the lip interior surface extending parallel and closely adjacent to the casing exterior surface. When the work platform tips or slides relative to the manhole casing, the cylindrical interlock lip engages either the cylindrical bore interior surface or the cylindrical casing exterior surface for thereby preventing the work platform from tipping or sliding off of the manhole casing.

What is claimed is: 
     
         1 . A work platform mounted on top of a manhole casing comprising a cylindrical casing exterior surface and a central bore having a cylindrical bore interior surface, the work platform comprising:
 a deck/frame structure; and   a cylindrical interlock lip secured to the deck/frame structure, the cylindrical interlock lip having a cylindrical lip exterior surface and a cylindrical lip interior surface;   wherein the cylindrical interlock lip is sized and shaped to either nest into the central bore with the cylindrical lip exterior surface circumscribed by and extending parallel and closely adjacent to the cylindrical bore interior surface or to fit snugly around the manhole casing with the cylindrical lip interior surface circumscribing and extending parallel and closely adjacent to the cylindrical casing exterior surface; and   wherein when the work platform tips or slides relative to the manhole casing, the cylindrical interlock lip engages either the cylindrical bore interior surface or the cylindrical casing exterior surface for thereby preventing the work platform from tipping or sliding off of the manhole casing.   
     
     
         2 . The platform of  claim 1 , wherein the cylindrical interlock lip is sized and shaped to nest into the central bore, wherein the cylindrical lip exterior surface includes a lip exterior diameter and the cylindrical bore interior surface includes a bore interior diameter, and wherein the lip exterior diameter is not more than 0.5″ less than the bore interior diameter. 
     
     
         3 . The platform of  claim 1 , wherein the cylindrical interlock lip is sized and shaped to fit snugly around the manhole casing, wherein the cylindrical lip interior surface has a lip interior diameter and the cylindrical casing exterior surface has a casing exterior diameter, and wherein the lip interior diameter is not more than 0.5″ greater than the casing exterior diameter. 
     
     
         4 . The platform of  claim 1 , wherein the cylindrical interlock lip is selectively coupled to the deck/frame structure. 
     
     
         5 . The platform of  claim 1 , wherein the deck/frame structure includes an access window which aligns with and provides access to the central bore. 
     
     
         6 . The platform of  claim 5 , wherein the cylindrical interlock lip circumscribes the access window. 
     
     
         7 . The work platform of  claim 1  further comprising a ring-shaped coupler disc that is secured to the deck/frame structure and the cylindrical interlock lip is selectively secured to the coupler disc. 
     
     
         8 . The work platform of  claim 7 , wherein the deck/frame structure includes an access window which aligns with and provides access to the central bore; and wherein the coupler disc and the cylindrical interlock lip circumscribe the access window. 
     
     
         9 . A work platform mounted on top of a manhole casing comprising a cylindrical casing exterior surface and a central bore having a cylindrical bore interior surface, the work platform comprising:
 a deck/frame structure; and   a pair of concentric first and second cylindrical interlock lips that are secured to the deck/frame structure, the first cylindrical interlock lip comprising a cylindrical lip exterior surface and the second cylindrical interlock lip comprising a cylindrical lip interior surface;   wherein the first cylindrical interlock lip is sized and shaped to nest into the central bore with the cylindrical lip exterior surface circumscribed by and extending closely adjacent and parallel to the cylindrical bore interior surface;   wherein the second cylindrical interlock lip is sized and shaped to fit snugly around the manhole casing with the cylindrical lip interior surface circumscribing and extending closely adjacent and parallel to the cylindrical casing exterior surface; and,   wherein when the work platform tips or slides relative to the manhole casing, the first cylindrical interlock lip engages the cylindrical bore interior surface and the second cylindrical interlock lip engages the cylindrical casing exterior surface for thereby preventing the work platform from tipping or sliding off of the manhole casing.   
     
     
         10 . The work platform of  claim 9 , wherein the manhole casing further includes an annular alignment protrusion extending upwardly from an upper end of the manhole casing, wherein the cylindrical lip interior surface and the cylindrical lip exterior surface define an annular interlock slot therebetween, and wherein the annular alignment protrusion is received into the annular interlock slot and engages the first and second cylindrical interlock lips to prevent the work platform from tipping or sliding off of the manhole casing. 
     
     
         11 . A work platform mounted on top of a manhole casing comprising a cylindrical casing exterior surface and a central bore having a cylindrical bore interior surface, the work platform comprising:
 a deck/frame structure; and   a plurality of arc-shaped interlock lips secured to the deck/frame structure, the arc-shaped interlock lips comprising arc-shaped lip exterior surfaces and arc-shaped lip interior surfaces;   wherein each arc-shaped interlock lip is sized and shaped to either nest into the central bore with the arc-shaped lip exterior surface there of extending parallel and closely adjacent to the cylindrical bore interior surface or to fit snugly around the manhole casing with the arc-shaped lip interior surface thereof extending parallel and closely adjacent to the cylindrical casing exterior surface; and,   wherein when the work platform tips or slides relative to the manhole casing, the arc-shaped interlock lips engage either cylindrical bore interior surface or the cylindrical casing exterior surface for thereby preventing the work platform from tipping or sliding off of the manhole casing.   
     
     
         12 . The work platform of  claim 11 , wherein the plurality of arc-shaped interlock lips includes three or more inner arc-shaped interlock lips and three or more outer arc-shaped interlock lips, wherein the three or more inner arc-shaped interlock lips are configured to nest into the central bore and engage the cylindrical bore interior surface, and wherein the three or more outer arc-shaped interlock lips are configured to fits snugly around the manhole casing and engage the cylindrical casing exterior surface. 
     
     
         13 . The work platform of  claim 12 , wherein the inner and outer arc-shaped interlock lips are arranged in parallel, concentric pairs that sandwich a portion of the manhole casing therebetween. 
     
     
         14 . The work platform of  claim 12 , wherein the inner and outer arc-shaped interlock lips are offset circumferentially from each other and form a staggered ring.