GB781147A - Improvements in core blowing apparatus - Google Patents

Abstract

781,147. Core-making machines. NEWBY, R. L. (Dodge Steel Co.). Dec. 9, 1955, No. 35371/55. Class 83 (1). A core-blower comprises a foraminous member through which sand is discharged into a core-box, and a gasket of sheet material covering the formainous area of the member and having a ported area in registration with one or more holes of said member registered with corebox cavity, the gasket closing those of the holes of the member not registered with the cavity or not required for the blowing operation, the gasket being retained in operative position with respect to said member by readily releasable means. The machine comprises a hopper 8 movable by a cylinder 15 between a position registering with a supply hopper 12, and a position registering with a pressure-fluid supply fitting 18 and above the core-box support 22, which is vertically reciprocable by a piston 21. A false-bottom structure 26 comprises spaced plates 27, 28 having aligned holes 31, 32 which, in the operative position of the structure, align with holes 29 in the perforated bottom 10 of the hopper 8. Additional holes 33 in the lower plate 28 communicate with the chamber 35 formed between the plates 27, 28, while the holes 31, 32 are connected by nipples 36 so as to form passages through said chamber from the underside of plate 28 to the upper side of plate 27, the upper end of said passages registering with the holes 29 when the plate structure is clamped to the bottom wall of the hopper by wedges 42 passing through slotted pins. The structure may be moved to the inoperative position, shown dotted in Fig. 2, on wheels 49. In operation, sand is blown into the core-box through the nipples 36, while displaced air is vented through the holes 33, into which are placed cup-shaped strainers 53. Alternatively, mesh-screening is incorporated in the plate 28. In order that the apertures 29 and registering nipples 36 which are not in communication with the core-box cavity or closed by the confronting surfaces of the core-box, may be sealed, a gasket 54, Fig. 13, is interposed between the hopper wall 10 and the plate structure 26, and provided with apertures 56 which register with the openings 29 which, through the nipples 36, communicate with the core-box cavity. Since the pattern of holes 56 will vary with different core boxes, the gasket is initially formed with a series of cored circles 59, corresponding in number and disposition with the holes 29 in the hopper bottom, and also with a pattern of etched circles on a transparent template 57, Fig. 12. The circles on the template are individually identifiable, and when the template is placed on the core box the position of the holes which should be made in the gasket 54 may be seen. The gasket may be of Kraft paper.