Patent GB-819807-A (GB)
Title: Cleaning rigid sheet surfaces
Inventor: MCCOWN WILLIAM ERNEST
IPC: B08B3/12
Filed: 1956-02-11
Abstract: 819,807. Cleaning curved glass sheets. LIBBEY-OWENS-FORD GLASS CO. Feb. 11, 1956, No. 4349/56. Class 138(1). A method and apparatus for cleaning rigid sheet surfaces (e.g. windshield glass) is characterised in that each sheet is moved through a liquid in a straight path relative to the vibrating faces of vibration generating elements imparting vibration energy to the liquid, and with both major surfaces of the sheet substantially equidistant from the vibrating faces. In the embodiment of Figs 1 and 2, curved windshield sheets S are carried from a feed conveyer 17 downwardly into a tank 11 containing water, detergent or acid 13, by an angled belt conveyer 18 onto a roller conveyer 14 from which they are removed by an angled belt conveyer 20 and carried to a discharge conveyer 19. The roller conveyer 14 passes between upper and lower banks 31, 30 of vibration generating elements 15 having working faces 36 which are arranged parallel to the surfaces of the sheet S and are spaced equidistantly therefrom. Rubber rollers 24 of the conveyer 14 are mounted on axles 25 journalled in supports 26 carried by the bottom of the tank 11. The axles each have a sprocket 27 drivable by a chain connected to the lower axle of the conveyer 20. The conveyers 14, 18 are connected in a similar manner and the conveyers 14, 18 and 20 are driven from an external source by a sprocket and chain attached to the upper axle of the conveyer 20. As seen in Fig. 1, the upper and lower outer rows of elements 15 are tilted to focus the vibrations along a relatively narrow path extending across the path of travel of the sheets. Each vibrator 15 is mounted by a rod 34 carried by a holder 35. The holders 35 are adjustably mounted in upper and lower plates 32, 33 and the lower rods 34 pass into the tank 11 through a gland G. The liquid 13 flows continuously through the tank 11 from an intlet pipe 21 to an outlet pipe 22, the latter being connected to a trough 23 at one side of the tank, into which trough scum can overflow. The vibrators may be piezoelectric, magnetostriction transducers or of a mechanised tyre such as an air hammer or whistle, and produce ultrasonic vibrations. In the embodiment of Fig. 5, the sheets S are carried into the tank 11<SP>1</SP> by conveyers 18<SP>1</SP>, 37, through rods 42, 43 mounted in a pivoted frame 44 carrying the vibrators 15<SP>1</SP> and out of the tank by conveyers 38, 20<SP>1</SP>. The conveyers 37, 38 are pivoted about their upper axles 39, 40 and are biassed to the horizontal position, and the frame 44 can pivot between the positions shown in full and dotted lines. As will be seen in Fig. 5, the sheets are carried lengthwise or the conveyers the weight of the sheet S causing the conveyer 37 to tilt. When the sheet contacts a roller 49 the leading edge is engaged by the rollers 42, 43. When the trailing edge of the sheet forces the conveyer 37 to its lowest position the frame 44 is caused to pivot clockwise by reaction. As the sheet passes through the rolls 42, 43 it engages the conveyer 38 and causes it to tilt and when the tracking edge of the sheet S leaves the rollsthe frame 44 is pivoted counterclockwise to its original position to receive the next sheet. The vibrators 151 are slidably mounted on the frame 44 and are urged towards each other by springs 47. The vibrators are moved against the springs to adjust themselves relative to the surfaces of the sheet by means of compensating rollers 48.