GB631053A - Improvements in and relating to sequential control apparatus for moulding machines - Google Patents

Abstract

631,053. Moulding- machines. STONE-WALLWORK, Ltd., and TAIT, W. Sept. 2, 1947, No. 24242. [Class 83 (i)] [Also in Group XXVIII] Moulding apparatus includes sequential control apparatus comprising a rotary cam-shaft having a plurality of cams operating a series of fluid-pressure valves, driving means for turning the cam-shaft and a device for stopping the driving means automatically at the end of a sequence of operations. The invention is described as applied to a moulding machine of generally known type comprising a head 1 on an arm 1<SP>1</SP> rotatable about its supporting column 2, a pneumatic jolt and squeeze unit 3 having a table 3<SP>1</SP> for carrying a pattern plate 4<SP>1</SP> and a mould box 4, vibrators 5 and a lift unit 6 with lifting pins 6<SP>1</SP> for raising the mould off the pattern. The machine may also include a mould filling arrangement to which the sequential control is also applied. This arrangement comprises a continuously rotated disc 52 to the outer part of which sand from a shoot 54 is distributed by a cone 55. Ploughs 57 movable to and from the disc by pneumatic cylinders 60 serve to push sand off the disc into one or more moulding boxes. The 'control apparatus comprises a casing 8 housing a motor-driven camshaft 9 beneath which is a rocker-shaft 12 carrying a rocker 13 for each of a series of cams 14 on the cam-shaft. Each cam comprises two discs 19 with lobes 20 which are relatively adjustable so as to vary the length of dwell and the cams are mounted in pairs on hubs 16 which are keyed to the shaft 9. The motor driving the cam-shaft is started by a pushbutton switch 27 and at the end of the sequence of operations is switched off by one of the cams. The pneumatic control valves are mounted beneath and to each side of the rocker shaft and are of the known poppet type adapted to be opened by the rocker shafts against the action of springs 32. In a typical sequence of operations, a mould box 4 is placed on the table 31 and the starter button is pressed. The head 1 moves into position over the box and jolting and finally squeezing takes place. The squeeze cylinder is then exhausted and the head 1 swung away. Next, the vibrators 5 are operated and the unit 6 lifts the mould box from the lattern. Finally, the lift cylinder is exhausted and the motor switched off. The control apparatus may also be applied to moulding machines of the turn-over type.