Patent GB-704773-A (GB)
Title: Improvements relating to centrifugal casting apparatus
IPC: B22D13/10
Filed: 1951-01-19
Abstract: 704,773. Foundry-plant. CONSTRUCTIONAL ENGINEERING CO., Ltd., and BROWN, K. S. April 18, 1952 [Jan. 19, 1951], No. 1514/51. Class 83 (1) Centrifugal casting apparatus for casting objects such as pipes comprises a casting machine, Fig. 1, a two-level track-system 16, 17, Fig. 2, a power-operated means 26 for lifting the mould 10 from the machine and delivering it to the upper track 16, along which it rolls under gravity, means for arresting the mould at a point in the upper track and for holding it while the casting is withdrawn, and means 49, Fig. 3, at the end of the upper track for transferring the mould on to the lower track 17, along which it returns under gravity to the machine. This may be of the type described in Specification 637,206, having a pneumatic cylinder 15 operating an arm 13 to hold the rotating mould 10 against the rollers 11. After completion of a casting operation, the arm 13 is raised to release the mould which is elevated by pivoted extensions 22 of the lower track 17 to the level of the pivoted extensions 20 of the upper track 16 which are tilted by the extensions 22 into the position illustrated in broken lines, causing the mould to roll onto the upper track. The jack 26 is controlled by the jack 15 to raise the mould at the end of the stroke of the jack 15. A trip 35 is depressed by passage of the mould and disengages a pawl 33 from a ratchet wheel 32, allowing the mould to proceed by rotating a gate 30 which releases a further mould on the lower track and allows it to pass to the machine; the extensions 22 having been lowered by the jack 26 which is controlled by a trip-over which the mould passed on its way to the gate 30. After passing the gate 30, the mould is arrested by the end of levers 36, positioned in gaps in the rails, until the levers are lowered by a jack 39, which allows the mould to roll on to the levers and be delivered to V-blocks 40. The mould is held on the blocks 40 as the casting is extracted by a clamp which may be lowered by a jack 42 operated automatically at a predetermined time after the clamping operation. The extractor (not shown) is mounted on a jack and may discharge the casting to a delivery track, an abutment on the extractor preferably reacting the extraction force. The levers 36 are then raised to discharge the mould from the V-blocks and deliver it to a pivoted stop 45 that may be lowered by a link 60 to allow the mould to continue to the rotary arms 49 where it actuates a pressure plate or trip-switch 50 which energizes a motor 48 to drive the shaft 47, supporting the arms 49, through reduction gearing and so lower the mould to the track 17, a limit-switch 51 then being arranged to stop the motor. The mould proceeds along the lower track towards the machine until arrested by a pivoted stop 52 connected to the link 60, and by a link 59 and lever 58, to a pair of levers 53 which are rocked by a jack 55. As the levers 53 are raised, a mould is released by each of the two-sided stops 45, 52, the lower mould passing on to the arms which, upon being lowered, deposit it on two pairs of spaced rollers 56 driven through gearing by an electric motor 57. The inside of the rotating mould is sprayed with refractory material to prepare it for its next casting operation, the spray preferably being controlled automatically by the drive to the rollers 56. After being raised from the rollers 56, the mould proceeds to a stop 61 held in the raised position by a preceding mould retained on the leading limb of the stop by the gate 30. Following the release of the preceding mould by the gate 30, the next mould is retained on the forward limb of the stop until it is released to roll on to the extension 22 and be delivered to the machine. The number of moulds in the circuit is decided by the temperature at which they are to be fed to the machine. At the end of a working shift, the end of the track 17 adjacent the arms 49 may be rocked by a screw 65 about a pivot 64 to discharge the moulds to a location where they are kept hot or stored ready for heating for the next shift. Further stops or regulators to regulate the movements of the moulds and controlled by timed mechanism, or by the passage of the moulds, or both, may be provided on the tracks, and selected ones may be interconnected. The controls on the casting machine may be linked with one or more of the stops on the track to stop the machine or the delivery of moulds in the event of a hold-up. The rails of the tracks are so spaced apart as to engage the grooves provided in the moulds to co-operate with the rollers 11. Additional grooves may be provided in the moulds to co-operate with the transferring mechanism and with the stops and regulators which may be arranged inside or outside the rails. The Provisional Specification describes also the use of a spray of water or air to assist in cooling the moulds and a counter-balanced bridge for lowering the moulds to the lower track.