Abstract: The present invention provides means for the improved positioning of a strongback in a pattern mold for formation of expendable patterns thereon. Investment casting molds formed around the assembly of strongback and patterns are characterized as having the strongback precisely and reproducibly suspended therein. Articles, such as turbine blade halves, cast in such investment molds have mating surfaces in close dimensional relationship and can be bonded one to any mating other to form a finished product.In particular, a strongback having bonding locators near the opposite ends thereof is provided with additional locators to be used in suspending the strongback in the pattern mold. According to the invention, these pattern mold locators are colinear with and in close proximity to the bonding locators and are engaged by locating means in the pattern mold for establishing precise positioning of the strongback therein.
Abstract: The present invention provides a method for improved positioning of a strongback in a pattern mold for formation of expendable patterns thereon. Investment casting molds formed around the assembly of strongback and patterns are characterized as having the strongback precisely and reproducibly suspended therein. Articles, such as turbine blade halves, cast in such investment molds have mating surfaces in close dimensional relationship and can be bonded one to any mating other to form a finished product.In particular, improved positioning of the strongback in the pattern mold is achieved by suspending the strongback from the bonding locators by expendable locating means; that is, locating means which are incorporated into the patterns formed on the strongback surfaces. The use of expendable locating means enables the bonding locators to also serve as locators for positioning the strongback in the pattern mold and essentially eliminates errors in strongback positioning due to tolerances associated therewith.
Abstract: An improved investment casting process for producing dental restorations, particularly a dental crown, comprising the steps of fixing a wax pattern onto a truncated cone in a metallic ring having a lining of a cushioning material, pouring an investment material into the space around the wax pattern in the metallic ring, drying the resultant product, melting out the invested wax pattern, curing the resultant product at a temperature of 700.degree. to 950.degree. C for 20 to 150 minutes to give a mold, fixing the mold thus obtained to a centrifugal casting machine and casting a molten chromium-cobalt and/or nickel alloy in the mold maintained at a temperature of 100.degree. to 500.degree. C.
December 31, 1975
Date of Patent:
November 29, 1977
Matsumoto Dental College, Sumitomo Chemical Company, Limited
Abstract: A precision investment casting ceramic mold of the self-casting type is made as a unitary mold by providing separately a pattern for a wax charge-holding assembly and a pattern for a wax article casting assembly, each including an alignment portion. The two patterns are secured together at the alignment portions and are supported and located one with respect to the other by a plurality of supporting and locating members. The assembled patterns then are used in the conventional manner to make a ceramic casting mold.
Abstract: An investment casting method for making a desired casting of a relatively large size by the use of a mold of one-piece construction within close dimensions, which comprises preparing a thermally fusible pattern which is a replica of the desired casting, forming a refractory investment enveloping the thermally fusible pattern, melting the thermally fusible pattern out of the investment leaving a cavity in the refractory investment, and heating the investment to provide a rigid ceramic mold of one-piece construction. Melting of the thermally fusible pattern out of the investment is carried out in contact with a vaporized organic solvent without causing the thermally fusible pattern to thermally expand which may otherwise result in formation of cracks in the refractory, investment, that is, mold.
November 6, 1974
Date of Patent:
December 14, 1976
Ken Ugata, Yasuji Morita, Yasuharu Mine
Abstract: A method of molding finger rings of the type having a hollowed-out interior portion, but whose exterior surfaces are identical to rings without such hollowed-out portion comprising securing a wax, shell ring pattern to the exterior surface of a wax, tubular section to form a wax ring pattern and molding a finger ring from said wax ring pattern via an investment method of casting.