Patent GB-873350-A (GB)
Title: Apparatus for transferring moulding boxes from conveyor means to the tables of moulding machines
IPC: B22C19/00
Filed: 1957-08-09
Abstract: 873,350. Conveyers; gripping devices for lifting loads. MEZGER, E. Aug. 9, 1957 [Aug. 24, 1956], No. 25279/57. Classes 78 (1) and 78 (4). [Also in Group XXII] Moulding-boxes 17 are transferred two at a time from a rollerway 1 to a pair of moulding- machines 2 arranged in a line at right-angles to the rollerway by two gripping-devices mounted for vertical movement on a horizontal jib 7, the jib 7 being secured to a column 6 which is rotatably mounted in the outer end of an arm 5 and the arm 5 in turn being rotatable about a vertical pin 4. This arrangement allows the boxes 17 to be transferred with a minimum clear space being required in front of the machines 2. In operation, the arm 5 and jib 7 are swung in opposite directions from the positions shown in Figs. 1 and 2 so that each lies in the direction of the rollerway with jib 7 overlying arm 5 (Fig. 3). After the gripping devices have picked up two moulds on the rollerway jib 7 is first swung anticlockwise (Fig. 3) through 60 degrees without moving arm 5. Then arm 5 is swung clockwise while at the same time jib 7 continues to swing anticlockwise relative to the arm, so that the outer end of the jib moves in a curved path in front of the supporting column (not shown) for the moulding-machines 2 until the jib 7 and arm 5 are fully extended into line transversely of the rollerway 1, as shown in Figs. 1 and 2. The gripping devices are then lowered and caused to release the moulds on to lower moulds 30 on the machines 2. The above operations are reversed for returning the jib 7 and arm 5 to the Fig. 3 position. The above swinging operations are performed by fluid pressure apparatus including an hydraulic pump drawing oil from a chamber 49 in the arm 5 and supplying it to a port 60 communicating with a steering cylinder 57 in the arm 5. Two further ports 61, 62 lead from the steering cylinder to a reversing valve. According to the position of the reversing valve the ports 61, 62 are arranged to communicate respectively with either the passages 50, 52, Fig. 3, or the passages 51, 53, the two passages not connected with these ports being connected to the reservoir 49 through the reversing valve. The passages 50, 51 and 52, 53 communicate respectively with opposite ends of arcuate chambers 41, 44 provided in the ends of the arm 5. Sector-shaped pistons 43, 46 respectively are arranged in the chambers 41, 44, the former piston being formed on the pin 4 and the latter piston on the column 6. A piston 56 arranged in the steering cylinder 57 is urged by a spring 58 towards the column 6 so that a roller 55 on this piston can follow a steering cam 54 on column 6. The piston 56 is provided with a cut-away portion to form an annular chamber 59. When the jib 7 and arm 5 are in line with the rollerway 1 the piston 56 is positioned so that oil can only pass from port 60 to port 61 so that when the reversing valve is appropriately operated only anticlockwise movement of the jib 7 is produced. When the jib 7 has swung through 60 degrees the port 62 is uncovered so that oil can pass from port 60 to both of the ports 61 and 62 resulting in simultaneous swinging of arm 5 and jib 7 in opposite directions until the positions of Figs. 1 and 2 is reached. Operation of the reversing valve causes these operations to be reversed. Each of the gripping devices includes a vertical rod 9 carrying at its lower end a bearer member 10 formed with a boss 18 on which a plate 19 is vertically slidable. Gripping fingers 21 are pivoted at 20 to the plate 19 and are connected by links 24 to the member 10. The gripping devices are raised and lowered by pinions 12 engaging rack portions on the rods 9 of the gripping devices, the pinions 2 being secured to a shaft 13 journalled in the jib 7 and driven by a reversible motor 16 on the jib. The gripping fingers 21 are normally maintained in the gripping position by the weight of the plate 19 but are automatically caused to release the moulding-boxes 17 when the gripping devices are lowered by providing guide-rods 28 which are secured to and depend from the jib 7, the guide rods having enlarged ends 27 which in the lowered positions of the gripping devices engage cup-shaped members 26 on the plates 19 to lift the latter, so causing the fingers 21 to move outwardly to release the boxes 17 from the rollerway 1. The gripping-devices are centred during lowering to pick-up the moulding-boxes 17 by pins 36 entering the apertures which are provided at the sides of the boxes to receive the pins 39 on the lower moulds 30. The pins 36 are carried on the ends of a bar 32 to which are secured bars 31 having slotted ends 37 which engage pins 38 on the fingers 21. The bar 32 is maintained centred by a pin 33 secured to it at its centre and engaging a bore 34 within the boss 18.