Abstract: An orthopaedic instrument includes a metallic load-bearing member and a non-metallic support structure formed integrally with the load-bearing member such that the load-bearing member is permanently attached to the non-metallic support structure. The non-metallic support structure enables the orthopaedic instrument to be lighter than an all-metal instrument while the metallic load bearing member provides wearability comparable to an all-metal instrument.

Abstract: A surgical cutting guide is adapted to receive a cutting instrument during a surgical procedure. The surgical cutting guide comprises at least one body portion including a bone engaging surface. A plurality of separate plates are secured to the at least one body portion. At least one cutting slot is formed in the surgical cutting guide between the plurality of separate plates. The at least one cutting slot is configured to receive the cutting instrument and orient the cutting instrument for the surgical procedure. The at least one body portion is comprised of a first material, such as a plastic material, and the plurality of separate plates are comprised of a second material, such as a metal material.

Abstract: A surgical cutting guide is adapted to receive a cutting instrument during a surgical procedure. The surgical cutting guide comprises at least one body portion including a bone engaging surface. A plurality of separate plates are secured to the at least one body portion. At least one cutting slot is formed in the surgical cutting guide between the plurality of separate plates. The at least one cutting slot is configured to receive the cutting instrument and orient the cutting instrument for the surgical procedure. The at least one body portion is comprised of a first material, such as a plastic material, and the plurality of separate plates are comprised of a second material, such as a metal material.

Abstract: An orthopaedic instrument includes a metallic load-bearing member and a non-metallic support structure formed integrally with the load-bearing member such that the load-bearing member is permanently attached to the non-metallic support structure.

Abstract: The investment casting process utilizes an investment assembly that includes one or more vents in each casting mold. Vents facilitate the extraction of the pattern material while preventing expansion of the pattern material to the extent that mold fracture or cracking results. The vents can be formed by incorporating within the patterns of articles to be cast one or more protrusions that cause the pattern to deviate from the size and shape of the article to be cast. After assembly of one or more patterns to a riser to form a cluster, the cluster is coated with a refractory material and the refractory material is removed from the protrusions either before the refractory dries or after the refractory dries, thus producing the vents.

Abstract: During the casting of reactive metals, the depletion of reactive elements from molten metal in an article mold cavity is prevented by blocking a feeder passage after filling an article mold cavity with the molten metal. To block the feeder passage, a valve member is floated on the molten metal. As the level of the molten metal rises, the valve member moves into sealing engagement with a valve seat. To make a mold structure containing the valve member, the valve member is positioned in a pattern of the mold structure. After covering the pattern with ceramic mold material, the pattern is removed to leave the valve member in the mold structure.

Abstract: An improved method of casting provides for the blocking of the upper end portion of a mold structure during preheating of the mold structure in a furnace and/or withdrawal of the mold structure from the furnace. The mold structure is raised into a furnace chamber with a cover blocking the upper end portion of the mold structure. In the illustrated embodiment of the invention, the cover moves upwardly through the furnace chamber to a location immediately above an upper sidewall of the furnace chamber. When the mold has been preheated, the cover is removed and molten metal is pored into the mold structure. The cover is then replaced on the mold structure. The molten metal in the mold structure is solidified by slowly withdrawing the mold structure from the furnace chamber with the cover blocking the upper end portion of the mold structure. Once the mold structure has been completely withdrawn from the furnace chamber and the molten metal in the mold structure has solidified, the cover is removed.