Patent GB-1459689-A (GB)
Title: Blasting device for cleaning relatively large surfaces
IPC: B63B59/06
Filed: 1974-07-02
Abstract: 1459689 Blasting SINTOKOGIO Ltd 2 July 1974 [12 July 1973] 29241/74 Heading B3D A blasting device comprises a packaged blasting unit 34 having an opening 95 which is brought into tight contact with a surface, such as a ship's side, gas tank, or wainscotting of a building, and through which abrasive material is projected on to the surface, a first frame means 18 having guiding arms pivotally mounted on the top end of a telescopic boom 7 swingable on a vehicle, a second frame means 24 engaged with the guiding arms and adapted to move along the arms, supporting means 31, 32 on the second frame means adapted to support the blasting unit 34 for movement substantially perpendicular to the guiding arms, a first operating means 20 for rotating the first frame means in relation to the boom, a second operating means 28 for moving the second frame means along the guiding arms, and a third operating means to move the supporting means and to bring the opening of the blasting unit into tight contact with the surface. The vehicle 1 is tracked 2 and has a turntable 4 supporting a rotating panel 5. Bearings 6 on the panel support a pivot 9 for the telescopic boom 7 which is movable about the pivot byÀan hydraulic cylinder 13. The boom has telescoping portions 8, 10, 11, 12, the upper portion 12 having brackets 17 for a pivot 19 about which the first frame is pivotable by the first operating means in the form of an hydraulic cylinder 20. The inner surfaces of the sides of the frame 18 form the guiding arms and receive rollers 25 on the second frame 24. An hydraulic cylinder 28 forming the second operating means is connected by ropes 26 to the frame 24 to effect movement thereof along the first frame 18. A supporting frame 32 is connected by crossed links 31 to the frame 24 and is movable by the third operating means (not shown) in the form of an hydraulic cylinder perpendicular to the plane of the frame 24. Brackets 33 on the supporting frame carry pivots 35 for the frame 40 of the blasting unit 34. The blasting unit 34 consists of a blasting chamber 39 fixed to a partition plate 41 having an opening 41a. A supporting plate 42 having an opening 42a is fixed to plate 41 and an impeller unit 36 is secured on a base 43 attached to plate 42. The impeller unit has a motor 46 driving rotary blades 44 and a distributer 54, and a control cage 57 for directing abrasive supplied by a shoot 69 and pipe 70 to the blades 44 to control the direction of the projection of the abrasive. The motor 46 is supported in a vibration absorbing manner on the base 43 by bolts 50 disposed within pairs of rubber tubes 49, and a rubber lining is disposed between the base 43 and plate 42. The lower end of the blasting chamber 39 communicates with a bucket conveyer 37 which transports the used abrasive to the shoot 69. The conveyer consists of two side rings joined by a cylindrical plate 64 formed with teeth 65 engaged by a pinion 67 driven by a motor 66 to effect rotation of the conveyer which is supported by pairs of rollers 60. Buckets are formed in the conveyer by partition plates 68 which extend between the side plates, and weirs provided inside each bucket prevent undue spilling of abrasive carried by the buckets when the blasting unit is used in an inclined position. The abrasive projected by the impeller unit passes through the openings 41a, 42a, in the plates 41, 42, the blasting chamber 39, and the opening 95 in the blasting chamber and impinges against the workpiece surface. The opening 95 is sealed against the workpiece surface in use by rubber sealing members 74. The unit 34 is supported by upper and lower pivots 78 in a supporting frame 40 carried by the pivots 35 from the brackets 33 so that the unit can align itself with the workpiece surface when engaged therewith, wheels 76 engaging the workpiece surface and a switch 79 providing an indication of correct engagement. A dust collecting duct 71 is connected between the blasting unit 34 to ducts 83 on the telescopic boom and to a dust collecting means 87 on an auxiliary vessel 86 coupled to the tracked vehicle 1, the auxiliary vessel also carrying a control board 91, generator 92, and oil pressure supply means for the hydraulic cylinders 13, 20, 28.