Patent GB-362425-A (GB)
Title: Mould and core making
IPC: B22C13/12
Filed: 1930-07-28
Abstract: 362,425. Moulding-machines; core making. STAHN, A., 6, Hohenzollernstrasse, Hanover, Germany. July 28, 1930, No. 22713. Convention date, Oct. 10, 1929. [Class 83 (i).] A mould and core-making machine has the moulding material projected horizontally into the flask or core box in the form of a solid jet, by means of compressed air which acts on the end of a column of material cut out from a supply contained in a closed drum. The drum 27, Fig. 1, is rotatably mounted on trunnions 26 and is provided around its end faces with a series of oppositely disposed and equally spaced holes 29, which are closed in all positions except the lowermost one by cover-plates 30; in this position the two lowermost holes are in register respectively with an annular rubber nozzle 31, and a tubular cutter 12 for projecting the moulding material. The flask or core box is mounted at the left of the machine on a table 51 slidable relative to the machine bed, and is held in position by adjustable plates 57, 58 ; the table is attached to cylinders 49, 50 into which fit differential pistons attached to the machine bed; by this arrangement the table is maintained in its extreme left-hand position by air pressure in the cylinder 49, but when air is admitted to both cylinders the table moves to the right, thereby pressing the flask or core box tightly against the nozzle 31 so that their openings are in register. The hollow cutter 12, exchangeably mounted by a nut 13 on a piston 6, which is displaceable horizontally in a cylinder 2, is operated by compressed air admitted through a valve 4 controlled from the front of the machine by a rod 5, Fig. 2 ; the cutter is returned after the moulding material has been ejected by a weight and chains. A valve 8 interposed between the end of the piston 6 and the hollow cutter 12 is opened by means of a lever 9 and rod 10 which can only operate when the cutter is tightly pressed against the nozzle 31 after having cut out a column of moulding material; when the lever 9 is raised air is admitted to the end face of the material to project it with high velocity into the flask or core box. A plunger 15 connected to a differential piston 16, removable from the machine by disconnecting a bridal-piece 20, serves to clear the cutter 12 of any residual material at the end of each working stroke ; during movement of the cutter the plunger remains in its extreme righthand position, but as soon as the valve 4 is closed, after the moulding material has been ejected, movement to the left takes place. A trip gear consisting of stop pieces 37, 37<1> on the cutter mounting, Fig. 2, and a rod 38 slidable on the bed, serve to control a valve 40 which admits air to the underside of a piston 41, Fig. 3 ; this movement of the piston effects, by means of ratchet gear on an arm 42 and a pawl 44, stepwise rotation of the drum 27 at the end of each working stroke of the cutter, this ensures that the moulding material in the drum is mixed and loosened after each operation. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the following features : (a) a suspended cylinder with air-operated piston having a cover-plate on the end of the rod to close any openings in the top of the core box; (b) means for using the openings in the revolving drum adjacent to the lowermost openings ; (c) pneumatic means for returning the hollow sand cutter to replace the weight. and chain mechanism previously described ; (d) two or more cutters for the sand acting together or separately, means for using two rotary drums, a hopper for supplying sand to the drums and a multiple header for filling several core boxes at the same time. It is also stated that a piston may be used for forcing the column of sand from the cutter. This subjectmatter does not appear in the Specification as accepted.