Method and apparatus for coating the inside of one or more hollow bodies with foundry sand or similar material, and particularly for moulding shells for casting bodies having the shape of a solid of revolution

摘要

341,673. Casting. POSSENTI, A., 29, Lungomare Nazzario Sauro, and SCORZA, C., 159, Via Andrea Costa, both in Pesaro, Italy. Dec. 16, 1929, No. 38460. Convention date, April 4. [Class 83 (i).] Moulding-machines; coating moulds.-Moulds or shells for pipe casting are lined with foundry sand by introducing the sand gradually into the shell whilst the latter is supported in an inclined position and rotated and compressing the sand as it collects in the shell. The shell 11 is rotatably supported on rollers 9 in supports 10 on a carriage 4 with track rollers 5 running on inclined rails 1 extending over a pit 3, the carriage 4 being jointed at 7 to the piston rod 6 of a hydraulic cylinder 8. A fixed support sleeve 48 is mounted parallel to the rails and carries a core 50 integral with a sleeve 49 connected to a rack 55 within the sleeve 48 whereby the core is movable along the sleeve 48. The shell 11 has an apertured flange 30 at the end for driving engagement with pins on a disc 28 on a shaft 19 rotating with but slidably mounted within a pulley 18 driven by an electric motor 12. The support sleeve 48 has collars 58, 59 supporting a rod 57 terminating adjacent the core 50 in a rammer 51, the rod 57 being reciprocated by a friction grip device 86 and a fork 83 connected to a crosshead 80 actuated by a rod 79 and crank 78 on a shaft 77 driven by an electric motor 70. Shaft 77 has another crank 73 actuating ratchet mechanism 74, 75, 76 and a pinion in engagement with the rack 55 connected to the core 50 for traversing the latter on the sleeve 48. Sand is supplied to a stationary mouth 45 round the sleeve 48 from a chamber 42, conveyer 43 and hopper 44 and a reservoir 66 is adapted to supply varnish to a pipe 64 extending through the sleeve 48. Fig. 1 shows a shell 11 in starting position for lining with the flanged end in driving engagement with the disc 28 on the shaft 19, or a number of shells may be treated at the same time side by side on the carriage 4, each having its own core, rammer and actuating gear. The conveyer 43 is operated to supply sand down the hopper 44 and as soon as sufficient sand has reached the bottom of the shell to fill the space between shell and pattern 31 on disc 28 the motor 70 is started to actuate the rammer and move the core 50 stepwise upwards along the sleeve 48, the rammer also moving progressively rearwards due to friction coupling 86. When the filling is complete the motor 70 is stopped, pressure is admitted above the piston of the hydraulic cylinder 8 to move the shell down the rails 1 and compressed air is admitted by tap 69 to the varnish reservoir 66 to supply varnish from the nozzle 65 of the pipe 64 whereby with the shell 11 still rotating the sand lining is coated with varnish. The driving disc 28 is now disconnected from the shell by rearward movement of shaft 19, the rails 4 are elevated to horizontal position by rod 40 of hydraulic cylinder 39, the pivoted bars 37, Fig. 3, are elevated by hydraulic cylinders 33, and the shell is removed across bridge rails 92. In a modification, Fig. 10, the rammers 51 are carried by a collar 95 sliding on the sleeve 49 of the core 50 and connected by a member 53 to a rack 96 engaged by a pawl 98 on a fork 99 reciprocated by the cross - head 80, the fork 99 carrying a friction clamp 86 engaging rack-bar 96 so that the latter is moved positively to the left and frictionally to the right; the core 50 is moved along the sleeve 48 by the collar 95 engaging the flange 491 of sleeve 49. In a further modification, Fig. 13, the rammers are in the form of inclined projections 106 on the core 50 sliding on a polygonal support 102 bushed at 118 and rotated within a bearing 103 by worm gearing 104, 105; the movement of the rod 110 connected to the core 50 is resisted to provide the necessary ramming pressure by friction blocks 111, Fig. 16, engaging the rod 110 and adjusted by a hand wheel 113 and tapering sleeve 112 screwed in the top end of the support 102.