Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
217 words
A method of joining mating pattern members (11,12,13) together along mateable margins to form an assembly, said pattern members (11,12,13) being comprised of rigid plastic foam, heat deformable at or above a temperature of about 79°C (175°F), the assembly being usable in the evaporative pattern casting process for casting metals, comprising; (a) applying a heat source (14) to a supply of hot melt adhesive to heat said adhesive to a liquid condition, said adhesive being characterised by a surface tension effective to permit said adhesive to be foamed by admixture with an inert gas, a softening temperature of 149-204°C (300-400°F), an inability to chemically attach said pattern members, a vaporisation temperature of 260° (500°F) or less, and an ability to remain in a nonsetting viscous liquid condition for at least 25-40 seconds after removal from said heating source; (b) extruding (16) a foam bead comprised of a mixture of said adhesive and an inert gas, said foam bead having a surface temperature of 77 0 c (170°F) or less, said extruded foam bead being deposited along selected mateable margins (20-32) of at least one of said pattern members (11,12,13); and (c) bringing at least a margin of one pattern member containing said foam bead into fixed mating relationship with a mating margin of the other pattern member.
Claim 2
Independent Claim
217 words
A method of joining mating pattern members (11,12,13) together along mateable margins to form an assembly, said pattern members (11,12,13) being comprised of rigid plastic foam, heat deformable at or above a temperature of about 79°C (175°F), the assembly being usable in the evaporative pattern casting process for casting metals, comprising; (a) applying a heat source (14) to a supply of hot melt adhesive to heat said adhesive to a liquid condition, said adhesive being characterised by a surface tension effective to permit said adhesive to be foamed by admixture with an inert gas, a softening temperature of 149-204°C (300-400°F), an inability to chemically attach said pattern members, a vaporisation temperature of 260° (500°F) or less, and an ability to remain in a nonsetting viscous liquid condition for at least 25-40 seconds after removal from said heating source; (b) extruding (16) a foam bead comprised of a mixture of said adhesive and an inert gas, said foam bead having a surface temperature of 77 0 c (170°F) or less, said extruded foam bead being deposited along selected mateable margins (20-32) of at least one of said pattern members (11,12,13); and (c) bringing at least a margin of one pattern member containing said foam bead into fixed mating relationship with a mating margin of the other pattern member.
Claim 3
Dependent Claim
27 words
A method as claimed in Claim 1, in which said pattern members are comprised of a material selected from the group consisting of polystyrene, polyurethane, and polyethylene.
Claim 4
Dependent Claim
15 words
A method as claimed in Claim 1 or 2, in which said adhesive comprises polypropylene.
Claim 5
Dependent Claim
33 words
A method as claimed in Claim 1, in which said adhesive is further characterised by an ability to retain bubbles for said foam, when formed, intact for at least 40 seconds after deposition.
Claim 6
Dependent Claim
20 words
A method as claimed in Claim 1, in which the surface tension of said adhesive is 50-150 dyne/cm at 60°C.
Claim 7
Dependent Claim
34 words
A method as claimed in Claim 1, in which said adhesive effectively sets up to a bonding condition within a time period of three seconds or less and without the use of added pressure.
Claim 8
Independent Claim
36 words
A method as claimed in any on of the preceding claims in which extrusion of said bead is carried out at a rate of .01 to 3 in 3 /ft for bead widths of .03-.5 inches.
Claim 9
Independent Claim
33 words
A method as claimed in any one of the preceding claims in which said extruded bead is effective to fill gaps between members as a result of volumetric expansion of said deposited foam.