GB557194A - Improvements in abrasive tools - Google Patents

Abstract

557,194. Moulding abrasive tools. TEAGUE, E. D., and NORTON GRINDING WHEEL CO., Ltd. June 25, 1942, No. 8737. [Class 87 (ii)] [Also in Group XXIII] In moulding abrasive tools having diamond or other abrasive bounded by a resinoid or like bond, a metallic powder is incorporated in the abrasive-bearing bond to form a localized wear-resisting skin. As shown, a cup wheel comprises a skin 3 united to the outer perimeter of a layer 2 of resinoid-plus-diamond powder formed on the face of a non-abrasive-containing form 1. The Fig. shows the assembly before the parts 2, 3 have been compressed. The invention may be applied to disc wheels carrying abrasive on the periphery or on the sides, or to honing sticks or stones. In making the wheel shown, the pre-moulded form 1 is inserted, together with a bottom plate 6 and arbor 7, into a mould 5. The exposed inner surface of the mould 5 is smeared with grease or with an adhesive such as glue or synthetic resin solution, the assembly 1-6-7 is removed and the preform 1 is cleansed of grease &c. Electrolytic iron powder of 300 mesh is spread over the grease &c., the mould being rolled on its circumference to promote even distribution. The loaded grease &c. is then trimmed to leave a skin 3. The assembly 1-6-7 is replaced, a hub member 8 is placed in position, diamond-resinoid mixture 2 is filled in to a depth 1/32-in. below the upper edge of the skin 3, and the mixture 2 and skin 3 are pressed by a member 4. The bond may be cured while the wheel is still in the mould, or after removal from the mould. It is found that the metal powder permeates the layer 2. If the metal-loaded grease &c. has spread over the top surface of the layer 2, the area affected may be ground. The form 1 may be moulded at the same time as the diamond-resinoid mixture is moulded. The metallic powder may be tin or copper. The bond may be shellac or rubber.