Patent GB-1187509-A (GB)
Title: Process and Apparatus for Cleaning with Dry Granules
Inventor: BODINE ALBERT GEORGE JR
IPC: B08B7/02
Filed: 1967-07-11
Abstract: 1,187,509. Cleaning. A. G. BODINE. 11 July, 1967, No. 31962/67. Heading B3D. [Also in Division F2] A process of cleaning a part, e.g. to break sand core material therefrom, comprises:- (i) Providing an elastic vibration system of which said part is a member; (ii) Immersing the part to be cleaned in a body of loose granular material; and (iii) Generating elastic vibrations in said system whereby the part is vibrated within said body of loose granular material. Apparatus for cleaning parts, e.g. to break sand core material therefrom, comprises:- (i) A body of loose granular material in which the part to be cleaned can be immersed; (ii) A vibration generator; (iii) A reactor capable of elastic vibration; (iv) A vibratory clamp to be engaged with the said part immersed in said loose granular material; and (v) Means for acoustically intercoupling said generator, said reactor and said clamp. A workpiece 10, e.g. a large stamping, a forging or a cast cylinder head of an I.G.E., is held by a clamp 11 against an elastically vibratory ring 12 on which a vibration generator 13 is mounted. An electric drive motor 15 for the generator 13 is supported by a bracket 14 extending from the ring 12 and having an eye 17 by which the entire assembly is supported through a cable 18 from an overhead support, e.g. a fixed support or a movable crane, so that it can be lowered into a body 19 of loose granular particles, such as sand, in a container 20. The ring 12 is of an elastic material of good fatigue properties, e.g. alloy steel. The bracket 14 has a platform 14a for support of the motor 15 and a split portion 14b having two legs 14c secured to the ring by screws 14d. The ring 12 engages one side of the workpiece near one end thereof, the opposite side being engaged by one edge of a clamp plate 24 mounted on the ring by a bolt 25 and nut 26. Toggle links 27, 28 engage at their outer ends the plate 24 and a support block 29 respectively and at their inner ends a joint member 30 which is forced inwardly to exert clamping pressure. The generator 13 has a body 35, secured to the ring 12 by screws 39, with a bore 38 forming a raceway for a roller 41 of lesser diameter than the bore and rotatably mounted on an axle 42 projecting from the hub of a spur gear 43. The pitch circle of the gear is of substantially the same diameter as the roller 41. The gear 43 meshes with an internal gear 44 formed or fixed within the body 35 concentrically with the bore 38 and having a pitch circle of substantially the same diameter as the bore. An axial pin 46 on the axle 42 rides around a circular boss 47 projecting from an end plate. The gear 43 is driven through shaft 50 and universal couplings 49, 51 by the motor 15, preferably a variable speed motor. The generator is driven at such a frequency as will cause the alternating force components applied normal to the ring 12 to create a condition of standing wave resonance in the vibrating system. In one mode the ring 12 is designed with constants of mass and elasticity so as to have a half-wavelength standing wave distribution of motion from generator to clamp, with antinodes at the generator and clamp and nodes at the points where the ring is mounted to the bracket 14; a transverse, one-wavelength standing wave is set up in the workpiece with antinodes at its ends. The generator may be driven at a harmonic of the fundamental frequency assumed for the above mode, e.g. the second harmonic, giving a one-wavelength standing wave across the ring 12 and a two-wavelength standing wave in the workpiece. In a modification, Figs. 7 and 9, standards 62 extending from a base 61 support a heavy bar 63 of alloy steel, the mountings comprising pins 64. Standards 69 are provided just outside the standards 62 to steady the latter or prevent longitudinal sway. A plate 70 supports an electric motor 71 and a bearing housing 72 for a shaft 73, the latter being driven by the motor through belts 74. The shaft 73 drives, through a shaft 75 and universal joints 73a, 78 a vibration generator 77. The body 80 of the generator engages a side of the bar 63 and is accurately located by pins 83. The outer side of the body 80 is engaged by a clamp plate 84 connected by tie rods 85 to a clamp plate 88 engaging the midregion of the outer side of a vertical workpiece 90. An hydraulic clamp comprises a member 93, through which the tie rods 85 pass, having a bottom wall 95 engaging the bar 63 and a wall 97 formed with a bore 99. Spacer sleeves 85a on the tie rods 85 are interposed between wall 97 and plate 88 so that the nuts on the tie rods can be set up tightly against plate 88. A piston 100 within the member 93 has a stem 101 passing through the bore 99 and carrying by a loose pivot 102 a clamp pad 103 engaging the side of the workpiece. Stem 101 has a ball end engaging a spherical seat 104 in the pad. To clamp, pressure fluid is admitted through line 105; to unclamp, pressure fluid is admitted through line 108 and passage 107. A box 110 for containing a body of particulate matter 111 is erected in the region to be occupied by the workpiece and may have access doors or an open top through which the workpiece may be introduced and positioned for engagement by the clamping means. The generator is driven at a frequency such that it sets up a transverse one-wavelength standing wave in the bar 63 and a transverse one-wavelength standing wave in the workpiece. The nodes of the wave in the bar 63 are located at the mountings of the bar. If the workpiece is short, a standing wave may not be developed therein, but the workpiece is bodily vibrated at sonic frequency. In a modification, Fig. 16, the vibration generator 77 is interposed between the centre of a vibratory bar 63a and a workpiece 90b arranged in general parallelism with the bar. In a further modification, Fig. 17, the vibration generator 77 is mounted to the mid-point of the bar 63 as before but the workpiece 90c is clamped at its mid-point to one end of the bar. In a further modification, Fig. 18, the vibration generator 77 is attached to one end of the bar 63 and the workpiece 90 is attached to the mid-point of the bar.