Patent GB-834763-A (GB)
Title: Improvements in blowing frame for tempering glass sheets
IPC: B23B3/18
Filed: 1958-10-10
Abstract: 834,763. Tempering glass sheets. PITTSBURGH PLATE GLASS CO. Oct. 10, 1958 [Dec. 19, 1957], No. 32432/58. Addition to 800,368. Class 56. Glass tempering apparatus comprises a blowing frame and means for supporting a glass sheet adjacent the frame, the frame comprising a plurality of parallel, spaced air supply pipes, each pipe having a plurality of passageways extending through a wall thereof for directing air streams towards the sheet, the passageways being formed in a series of groups with mutually divergent passageways, each group being disposed in a triangular array and/or the jets of air impingeing on the glass surface in patterns substantially uniformly distributed thereon. Two blowing frames 17, 18 consisting of supply pipes 10 are arranged either side of a glass bending mould M on which the glass sheet A is supported, each pipe 10 being pivotally mounted by a union socket 11 and connected thereby for air supply to feeder pipes 12, 13, flexible hoses 14, 15 and thence to main air supply conduits 16. The pipes 12, 13 support the pipes 10 and are adjustably slidably mounted in frames 17, 18 on the conduits 16 so that the pipes 10 can closely follow the shape of the curved glass sheet A. The conduits 16 are mounted on an oscillating main frame 36 by side pipes 27, 29 and 31 which connect the conduits by flexible pipes 32 to a reservoir and compressor installation. The frame 36 is mounted at the rear on ball mountings 37 and at the front on eccentric mountings 38 driven through gearing 38a and shaft 39 from a motor (not shown) to give a small oscillation parallel with the central portion of the glass sheet A so that the pipes 10 adjacent the bent-up ends will move towards and away from the sheet. The oscillation may not be used at all for small sheets and an oscillation of from one to one and a half inches diameter is satisfactory for larger sheets instead of the more usual two and three quarter inch diameter. Each pipe 10, Fig. 13, has a large number of nozzles 40 arranged in a continuing triangular pattern in three mutually parallel rows, the outer rows being formed in flat outer surfaces 41, 42 at an angle slightly greater than 180 degrees and the inner row, in staggered relation to the outer rows, in flat surfaces 43 at equal angles to the two surfaces 41, 42 so that the nozzles 40 direct air in mutually diverging planes X, Y, Z. The nozzles 40 on adjacent pipes 10 are staggered and the pipes spaced apart a distance S at least as great as the diameter D of each pipe so that the surface of the glass A, Figs. 13, 15, is substantially uniformly covered by the jets, typical areas of coverage of each jet being shown by the circles, and there is a wide area for escape of spent air as indicated by arrows 80. When the frame 36 is oscillated, smaller areas of covereage may be provided, the oscillation ensuring the uniform distribution. The nozzles 40, which are screwed into the pipe wall, have passageways of decreasing taper as in Specification 800, 367, preferably in at least five conical sections 45, 46, 47, 48 and 49 of successively decreasing taper.