Method of making and using molds for longitudinally curved sections of pipe insulation

Claim 1

A method of making a longitudinally curved section of foamed resin pipe insulation having a glass fiber reinforced resin outer jacket, the method comprising making a first mold by mounting a plurality of flat, semicircular ribs of a relatively large radius in an arcuate pattern and in arcuately aligned, spaced relationship on a first board with each rib having a diametral portion of its periphery facing the board and extending generally radially of the arcuate pattern, and foaming a foamable, hardenable liquid resin in place between each pair of adjacent ribs to provide foam segments between the ribs, making a second mold by mounting a plurality of flat, semicircular ribs of a relatively small radius in an arcuate pattern and in arcuately aligned, spaced relationship on a second board with each rib having a diametral portion of its periphery facing the board and extending generally radially of the arcuate pattern, and foaming a foamable, hardenable liquid resin in place between each pair of adjacent ribs to provide foam segments between the ribs, forming a glass fiber reinforced resin outer jacket on the first mold, removing the outer jacket from the first mold, placing the outer jacket in juxtaposition with the second mold, foaming a foamable, hardenable liquid resin in place between the outer jacket and the second mold to produce a longitudinally curved section of foamed resin pipe insulation having the glass fiber reinforced resin outer jacket adhered thereto, and removing the pipe insulation with the outer jacket from the second mold.

Claim 2

A method of making a longitudinally curved section of foamed resin pipe insulation having a glass fiber reinforced resin outer jacket, the method comprising making a first mold by mounting a plurality of flat, semicircular ribs of a relatively large radius in an arcuate pattern and in arcuately aligned, spaced relationship on a first board with each rib having a diametral portion of its periphery facing the board and extending generally radially of the arcuate pattern, and foaming a foamable, hardenable liquid resin in place between each pair of adjacent ribs to provide foam segments between the ribs, making a second mold by mounting a plurality of flat, semicircular ribs of a relatively small radius in an arcuate pattern and in arcuately aligned, spaced relationship on a second board with each rib having a diametral portion of its periphery facing the board and extending generally radially of the arcuate pattern, and foaming a foamable, hardenable liquid resin in place between each pair of adjacent ribs to provide foam segments between the ribs, forming a glass fiber reinforced resin outer jacket on the first mold, removing the outer jacket from the first mold, placing the outer jacket in juxtaposition with the second mold, foaming a foamable, hardenable liquid resin in place between the outer jacket and the second mold to produce a longitudinally curved section of foamed resin pipe insulation having the glass fiber reinforced resin outer jacket adhered thereto, and removing the pipe insulation with the outer jacket from the second mold.