Patent GB-993414-A (GB)
Title: Method of and apparatus for, burning off the moil, from hollow glassware
IPC: C03B33/085
Filed: 1961-08-11
Abstract: In burning-off moil from hollow glassware by rotating the ware in a ring burner at the line of severance and applying a constant tensile force to the moil during heating until the heated glass separates, this burning-off period is used to control the subsequent burning-in <PICT:0993414/C1/1> period during which the edge of the severed ware is smoothed by heating in the burner.  The control may be direct, i.e. equal times, or a set proportion, or may have a further control by which the burning-in period is gradually lessened in proportion with longer burning-in periods.  As shown, an article 10, with moil 16, is held by suction through hollow shaft 18 rotatably mounted on a carrier 6 sliding on main column 2 and guided by sleeve 3 on column 21, both columns supported on a base 1.  Burner 11 on carrier 7 and clutch 12 on shaft 19 rotatably mounted on carrier 8 are similarly mounted by sleeves 4, 5 on the columns 2 and 21, the carriers being adjustable for varying size articles, so that in operative positions, the line of severance 14 lies in the plane 15 of the burner flames and the clutch 12 can engage the moil 16. The article 10 is centred, by an oscillating element 17, with respect to the burner 11 when the article is raised to just below burn-off position, where a weight 25 on the arm 36 of handle 13 strikes the piston-rod 26 of an air cylinder 27. Shaft 19 and clutch 12 are then moved down by a handle 20 pivoted at 201 to the main column 2 and joined by rod 21 to a lever arm 22, pivoted at 221 to column 2, acting on the top of shaft 19 and having a counterweight 23.  A mercury switch on arm 22 closes a line to a three-way valve 30 so as to connect the air line 31 to atmosphere at 48 thereby releasing air from cylinder 27 through line 32 and three-way valve 33, so that handle 13 can move to its uppermost position. At the same time the pressure on side A of a differential four-way valve 34 is released. Movement of handle 13 brings the article 10 to the burn-off position and arm 36 presses the switch lever of a three-way valve 37 to admit compressed air to the B side of valve 34, which has about half the pressure surface of the A side. Air is thereby admitted above the oil in a tank 39, the oil passing valve 40 to cylinder 42 to move piston-rod 43 to the right, as shown, and thereby pressing oil into tank 38 through valve 41, both valves 40, 41 allowing free flow in the direction of the arrows. Lever 44, moved by piston-rod 43, switches over valve 33 to connect cylinder 27 with atmosphere.  When the burning-off period is finished and the moil separated, clutch 12 moves upwardly under weight 23 and mercury switch 46 is switched off to return valve 30 to the position shown, thereby admitting air to the side A of valve 34, which being greater pressure than side B, reverses the pressure from tank 39 to tank 38 to start the burning-in period.  The time is adjusted according to the length of the burning-off period by valve 41, set normally to give a period of one-fifth of the burning-off time.  To further regulate the time, lever 44 moves a rod 45 which is hinged to the disc of valve 41 so that for large movements of lever 44 (i.e. long period of burning-off) rod 45 has similar large movements to vary setting of disc to give slightly less burning-in time.  On return of the lever 44 at the end of the burning-in period, valve 33 is switched to admitted air from line 31 to line 32 and the end of cylinder 27 and push weight 25 upwardly by its piston-rod 26, thereby lowering the article 10 a short distance, out of the range of the burner.  Valve 37 is released and pressure on side B of valve 34 stopped.  Handle 13 can then be lowered and the article removed. U.S.A. Specification 1,577,538 is referred to.