GB1233441A - - Google Patents

Abstract

1,233,441. Moulding machine; transportation of finished moulds. E. BUHLER. 19 Aug., 1968 [18 Aug., 1967; 27 April, 1968], No. 39629/68. Heading B3F. A method of producing horizontally-divided sand moulds comprises the steps of (i) introducing sand pneumatically into two mould frame cavities formed above and below a pattern plate D, each of said cavities being defined by vertically movable mould frames Ca, Cb and vertically movable press rams Ba, Bb (Fig. 1); (ii) compacting the sand by relative movement between said press rams and the pattern plate; (iii) separation of the pattern from the mould halves by relative movement between the press rams and mould frames on the one hand, and the pattern plate on the other hand (Fig. 3); (iv) moving away laterally the pattern plate into an inoperative position; (v) closing the mould; (vi) uncovering the mould by relative movement between the press rams and the mould frames (Fig. 5); and (vii) shifting the mould laterally on to a conveying means, by moving the pattern plate back from its inoperative position to its moulding position, where it joins a continuous line of moulds moving past the pouring position. Only the pushing force required for the lateral ejection of the finished mould is derived directly from the pattern plate-the pushing force required to advance the line of moulds is transmitted thereto by way of the means supporting said line of moulds. The pattern plate (Fig. 10) comprises a main frame part 1 having upper and lower frame parts 1<SP>1</SP> and 1<SP>11</SP> respectively articulated thereon. These parts 1<SP>1</SP> and 1<SP>11</SP> are provided with shoulders to which a top plate 9<SP>1</SP> and a bottom plate 9<SP>11</SP> are detachably fastened. The plates 9<SP>1</SP> and 911 are provided with a large number of holes 12 into which holding means for the patterns can be introduced. The hollow interior of the pattern plate may be connected to a vacuum source, to assist the feeding of sand into the mould frame cavities, or a compressed gas source to assist detachment of the finished mould from the pattern. The pattern plate may be held in a cross-slide frame, Fig. 15 (not shown), which permits shifting of the pattern plate relative to the moulding machine in two directions at right angles to one another so that the pattern plate can be moved in both directions by at least one plate width out of its moulding position; one of the two cross-slides co-operates with the ejection ram for the finished moulds. More than one pattern plate may be accommodated in such a cross-slide frame, thus permitting the pattern to be changed on that pattern plate which is not in the operative position. The pattern plate may be heated by infra-red radiators when it is in its inoperative position. The conveying means for the finished moulds may be in the form of an endless steel band supported by rollers or it may be in the form of an oblong bench whose surface is formed of longitudinal guide bars along which the finished moulds slide (Fig. 16). In this embodiment, the pattern plate D is pulled back into its moulding position by means of an hydraulic drive acting on fork elements 121 and thus ejects the last finished mould. After a certain idle run, the hydraulic drive also acts on fork elements 125 which bear against supporting means 128 for the finished moulds and thus advance the mould train. Said supporting means comprises clamp ing plates 142 disposed opposite one another in pairs and attached via vertical levers to a horizontal loading plate 137 and a weight 129 movable in a vertical guide 135. The supporting units may be moved along an overhead rail 132 which has a lowerable section 134 above the point where the conveyer track adjoins the mould making machine. When the plate 137 is lowered on to the surface of the mould, the clamping plates 142 bear against and thus support the sides of the moulds. Vertical elastic strips 147 may be attached to the front edges of the clamping plates 142 to bear against the adjacent plate and thus ensure that the thrust exerted by the sliding forks 125 will be transmitted to the whole of the mould train. The moulding sand may be introduced into the mould frame cavities either through slots in the mould frames Ca, Cb (Fig. 1) or through holes in the press rams Ba, Bb (Fig. 18). The arrangement for introducing moulding sand shown in Fig. 18 comprises a gas compressor 150, a compressed-gas reservoir 151, a moulding- sand container 154 fillable from a moulding-sand bin 164 and two compressed-gas ducts 153a, 153b located between the compressed-gas reservoir 151 and the moulding-sand container 154. The walls of the upper and lower chambers 155a and 155b of the moulding-sand container are formed by the ring cylinders of the hydraulic drives Fa, Fb for the press dies Ba, Bb and the telescopic extensions 106 adjoining the press dies. Moulding sand is supplied to the moulding- sand container 154 from the bin 164, the closure plate 169 is then moved to its closed position and the moulding-sand forced into the mould frame cavities by compressed gas supplied from the reservoir 151 via control valves 152a and 152b.