Pipeline patch trolley

A vehicle for transporting and installing an annular patch in a pipeline having a cylindrically curved inside surface, said vehicle comprising:

• a tubular support member having a substantially cylindrical exterior and a hollow interior;
• an annular bladder mounted on said cylindrical exterior of said tubular support member for forcing said patch against said inside surface of a pipeline in response to inflation of said bladder;
• at least first and second pivoting wheel assemblies mounted at each end of said tubular support member, said wheel assemblies at each end of said tubular support member being mounted at angularly spaced locations so as to define an included angle between said wheel assemblies, each said wheel assembly comprising:
• a caster pivot mounted to said tubular support member so as to define a pivot axis that extends substantially radially from said tubular support member;
• and
• a roller wheel mounted to said caster pivot so as to pivot about said radially extending axis, so that said roller wheel is aligned substantially normal to said cylindrically curved inside surface of said pipeline when bearing thereon;
• and
• at least one ballast weight mounted inside said tubular support member within said included angle between said wheel assemblies, so as to maintain said vehicle in an upright orientation as said vehicle moves longitudinally through said pipeline.

A vehicle for transporting and installing an annular patch in a pipeline having a cylindrically curved inside surface, said vehicle comprising:

• a short length of pipe forming tubular support member having a substantially cylindrical exterior and a hollow interior;
• an annular bladder mounted on said cylindrical exterior of said tubular support member for forcing said patch against said inside surface of a pipeline in response to inflation of said bladder;
• a compressed air fitting for supplying compressed air to said annular bladder, said fitting being mounted inside said support member for attachment to a compressed air line extending through said pipeline and into said hollow interior of said tubular support member;
• at least first and second pivoting wheel assemblies mounted at each end of said tubular support member, said wheel assemblies at each end of said tubular support member being mounted at angularly spaced locations so as to define an included angle between said assemblies, each said wheel assembly comprising:
• a caster pivot mounted to said tubular support member so as to define a pivot axis that extends substantially radially from said tubular support member;
• a roller wheel mounted to said caster pivot so as to pivot about said radially extending axis, so that said roller wheel is aligned substantially normal to said curved inside surface of said pipeline when bearing thereon, and
• means for selectively pivoting said caster pivot and said roller wheel inwardly towards said interior of said tubular support member so as to provide clearance for sliding said annular patch over said tubular support member and said inflatable bladder thereon, said means for selctivley pivoting said caster pivot and said roller wheel inwardly comprising:
• a first bracket member mounted to an inside lip of said pipe and having a sleeve portion mounted thereon;
• a second bracket member having said caster pivot and said roller wheel mounted thereto, and a second sleeve portion mounted thereon so as to be in coaxial alignment with said first sleeve portion when said second bracket member is in a deployed position;
• a hinge interconnecting said first and second bracket members so that said second bracket member is pivotable from said deployed position, in which said second bracket extends outwardly from said pipe so that said roller wheel bears against said inside surface of said pipeline, to a retracted position, in which said second bracket member extends towards said interior of said length of pipe so that said roller wheel is withdrawn within an outside diameter of said pipe;
• and
• a locking bolt for passing through said sleeve portions when coaxially aligned so as to lock said second bracket member in said deployed position, said locking bolt being selectively withdrawable from said sleeve portions so as to unlock said second bracket member to be pivoted to said retracted position;
• and
• at least one ballast bar mounted lengthwise inside a bottom of said tubular support member within said included angle between said wheel assemblies, so as to maintain said vehicle in an upright orientation as said vehicle moves longitudinally through said pipeline.