Patent GB-1422888-A (GB)
Title: Pendulous blasting apparatus
IPC: B24C3/06
Filed: 1973-12-27
Abstract: 1422888 Blasting SINTOKOGIO Ltd 27 Dec 1973 [11 June 1973] 59730/73 Heading B3D A pendulous blasting apparatus comprises means 81, such as a rope, for suspending the apparatus for blasting of a surface, such as the side of a ship, or bridge, and centrifugal projecting means 3 for projecting abrasive through an opening 10 on to the surface, the opening being surrounded by a seal 38 which is urged against the surface by electromagnets 9. Abrasive recovery means is mounted on the apparatus and includes a hopper 34 for receiving used abrasive and a bucket conveyor 4 for carrying the abrasive to the projecting means, a separating means removing dust from the abrasive by means of air suction. Wheels 8 permit the apparatus to be moved vertically over the surface and are driven to move the apparatus laterally over the surface. The apparatus has a blasting chamber 7 in which is formed the opening 10 and which has a rear plate 26 supporting the conveyor casing 5. A plurality of rollers 12 are mounted in the casing 5 and engage the outer wall of the conveyor which is also formed with gear teeth 14 engaging a gear 20 driven by a motor 19. The conveyor consists of a plurality of buckets 13, each bucket having a weir 13b which assists in retaining abrasive in the buckets when the apparatus is used to clean an inclined surface. A separating chamber 6 is disposed in the upper part of the casing 5 and consists of an inclined plate 21, formed with an opening 22 leading to the projecting means 3, and an inclined plate 23 spaced from plate 21 to form a passage 24 along which any abrasive not supplied to the opening 22 passes to an opening 36 leading to the conveyor. Air inlets 25, 26 are provided in the casing 5 and plate 26, and an opening 28 is provided in inclined plate 21. An outlet 31 is connected by a duct 30 to a dust collector to withdraw dust from the separating chamber 6 through a removing chamber 37 formed by a plate 35. The opening 10 of the blasting chamber has a double sealing member 38 of rubber or the like for engaging the surface to be cleaned. The opening 22 from the separating chamber communicates with a shoot 29 leading to the projecting means 3 which consists of a bladed impellor 39 and distributor 48 driven by a motor 11, and a stationary cage 51. The centrifugal projecting means are resiliently supported on the plate 26 so as to reduce vibration. A labyrinth seal 52 and deflector 53 protect the bearings of the motor. The frame 2 has bearings 55 for a pair of shafts 56, each end of each shaft having a pair of wheels 8, the peripheries of which are formed with recesses containing rubber covered rollers 59 mounted to rotate about axes lying in the planes of the wheels. Sprockets 64 on the shafts are connected by chains 71 to sprockets 69 driven by a gear reduction unit 68 from a motor 66. The frame 2 also has a plurality of brackets 72 for annular rubber cushions 73 supporting electromagnets 9 which are disposed in a plane behind the operative portions of the wheels 8 and which act to urge the apparatus, and particularly the seal 38, against the surface to be cleaned. Brackets 76 are mounted on the frame 2 and support pins 78 connected by wires 78 to a rod 80 in turn connected to a rope 81. The apparatus is suspended by the rope 81 and the electromagnets urge the apparatus towards the surface which may be vertical or inclined, the pins 78 permitting tilting movement of the apparatus. Vertical movement of the apparatus is permitted by rotation of the rollers 59 of the wheels 8, while lateral movement is effected by rotation of the wheels by the chain drive 71.