GB1079078A - Improvements in manufacture of refractory shell molds - Google Patents

Abstract

1,079,078. Refractory slurries formed on patterns. HOWMET CORPORATION. Aug. 19, 1965 [Sept. 21, 1964], No. 35609/65. Heading B5A. A refractory-mould forming machine for automatically producing sanded refractory slurry coatings on patterns comprises a rotatable mount 25 with indexing means for turning the mount through a series of hold positions 22, one rotatable spindle 16 for each pattern 17 which may be pivotally fixed on the mount, radially disposed thereon, and adapted to hold the associated pattern at the outer end of the spindle, at least the outer end of each spindle being translatable dip tanks for refractory slurry 29 and sanding material 28, each located adjacent to the mount at different hold positions of the mount, drive means for rotating each spindle, means for displacing at least the outer end of the spindle when adjacent to the dip tanks to dip the pattern thereinto. The spindles may be spaced at uniform angular intervals corresponding to the angular spacing between hold positions. The spindles may be individually rotatable by a motor and are preferably rotated continuously, preferably between 5 and 25 r.p.m. The sanding material may be fluidized in its dip tank so as to apply sanding without disturbing the slurry coating. There may be a track 44, Fig. 12, (not shown), surrounding the mount on which the spindles are supported by rollers 39A except where it is indexed adjacent the dip tanks, where lift means 37, are provided on to which each spindle support rolls. The pattern on the spindle may be lowered into the slurry to an angle of 20- 50 degrees, preferably 30 degrees, below the horizontal and then raised to an angle of 20-50 degrees, preferably 30 degrees, above the horizontal. There may be means for hardening the slurry coating between the sanding material dip tank and the slurry dip tank, preferably comprising an arcuate chamber 64 containing a gas conducive to hardening the coating, extending concentrically around the greater part of the mount. The chamber preferably has a pair of extended resiliently engaged displaceable seating members 91, 92 covering a slot around the inner chamber wall to permit the spindles to project through and move along the slot without substantial escape of gas, and entry and exit doors 85 at each end of the chamber adapted to open before and close behind each pattern as it is carried into and out of the chamber.