Patent GB-232279-A (GB)
Title: Method of, and apparatus for supplying abrasive to sheet glass surfacing machines
IPC: B24B57/00
Filed: 1923-11-05
Abstract: 232,279. Golby, F. W., (Libby-Owens Sheet Glass Co.). Nov. 5, 1923. Systems controlling travel for a fixed distance of number of revolutions; systems depending on the use of two of more motors.-Abrading material in suspension in water is supplied to a series of sheet glass grinding machines from pipe lines which extend adjacent to the machines. the material being supplied automatically by electrically controlled devices for the periods required. In apparatus employing three grades of abrasive these are maintained in pipe lines 11, 12, 13 extending past the several grinding machines 7. Opposite each machine are three valves 14. 15, 15, Fig. 7, which discharge into a funnel 17, from which it flows to the feed pipe of the machine. The valves, which are of the rotary step cock type, are operated by levers 191 which are moved by arms 193 adjustably mounted on push rods 21. These rods slide in bearings on a frame 27 and are normally lifted by springs 25, they are depressed to open the valves by cams 30, 31, 32 on a shaft 29 rotated at the desired intervals by an electric motor 33 through gearing 34 - - 37. The supply of abrasive is controlled by means of an arm 39 moved bv an electric motor 40 around a dial 38 carried by the grinding machine. The dial carries a starting pin 41 and an adjustable stopping pin 42 with which contacts on the arm are adapted to make a connection. At starting the arm is turned manually counterclockwise to contact with the pin 41. A lead 43 from the positive main is connected with a ring 44, Fig. 8. with which a brush on the arms makes contact, a lead 45 connects with pin 41, and a lead 46 connects to a ring 47 on back of dial with which pin 42 makes contact when inserted in any one of a series of holes in the dial. The motor is connected to the main by a lead 47<1> and a lead 48 from motor, and leads 45, 46 go to auto matic starting, stopping and reversing switches. when the arm 39 is moved to contact with pin 41, the grinding commences and continues un@@ the arm contacts with pin 42, the arc between these pins determining the grinding time. To control the supply of abrasive, the dial has thereon rings 49, 50 into any one of a series of holes in which pins 51, 52 may be inserted; the arm connects these pins as it rotates with ring 44. Upon a dial 54 carried by housing for gears 34 - - 37 are four contact pins 55 - - 58 connected respectively to pin 41, ring 49, ring 50 and ring 47, and in the dial is a ring C3 connected to one terminal of motor 33. On the shaft 29 is a quadrant 66 carrying a contact plate 67 in continuous contact with ring 63 and adapted to contact in succession with pins 55 - - 58. At starting, with plate 67 just off pin 58 and just on pin 55, a circuit is completed from the positive main through wire 43, ring 44, arm 39, pin 41, wire 49, pin 55, plate 67, ring 63, wire 64, motor 33 and wire 65 to the negative main. The motor 33 rotates the shaft 29 clockwise 90‹ until the plate 67 runs off contact 55 and on to contact 56. This moves down cam 50 and opens valve 14 allowing a supply of coarse abrasive. When arm 39 has moved to contact with pin 51 a new circuit is made through pin 56 and motor 33 rotates shaft 29 another 90‹, shutting valve 14 and opening valve 15 and supplying the intermediate grade of abrasive, Similar operations take place to supply the finest grade of abrasive after which the arms contacts with pin 42, when the motor 33 rotates until all of the valves are closed and the machine stops.