Patent GB-335249-A (GB)
Title: Improvements in apparatus for cutting glass tubing
IPC: C03B33/085
Filed: 1929-06-20
Abstract: 335,249. Johnsen & J÷rgensen Flint Glass, Ltd., and Ashford, E. June 20, 1929. Cutting glass. - Relates to apparatus for cutting glass tubes into lengths by means of a flame. The invention consists in providing means for causing the flame to impinge on the surface of a rotating tube at a constant angle irrespective of the shape of the tube. The tube 11, Fig. 1, is clamped in a rotating chuck 100 and is heated, at the place where it is to be cut, by the flame from a jet 13. Metal rollers 12 are pressed into contact with the tube along the line heated by the flame, and the strain set up in the hot glass by the chilling effect of the metal rollers, causes it to crack. The chuck 100 is journaled in a bearing 8 mounted on a frame 2, and it is rotated by a belt pulley 10. A collar 84, embraced by a forked lever 83, opens the chuck to release the tube 11, the chuck normally being kept closed by a spring 88. The rollers 12 are supported by a stem 17, Fig. 3, which slides through apertures in a sleeve 15 secured to a pair of parallel guide rods 5 forming part of the frame 2. A spring 19 surrounds the stem 17 and forces the rollers upwards into contact with the tube 11. The jet nozzle 13 is connected by a flexible pipe 36 with a supply of gas, and it is clamped to a lever 32 which is pivoted to the upper end of a rod 27 adjustably connected to an extension 26 of the sleeve 15. The forward end of the lever 32 carries at one end a roller 35 which is kept in contact with the tube 11 by a spring 40 that acts on a rod 38 pivoted to the tail end of the lever 32. The stem 17 and the rod 38 can be drawn downwards by a lever 22 which has one end upheld by a spring 101 while the other end carries a roller 24 that rests on a cam 25 secured to a shaft 7. This shaft is rotated continuously, so that the lever 22 is rocked periodically by the cam 25 and moves the jet nozzle 13 and the rollers 12 away from the tube 11. A feeding device is also provided for feeding the tube 11 periodically through the chuck 100 so that it can be cut into pieces of predetermined length. The device consists of two automaticallyoperated gripping-devices 150 arranged before and behind the chuck 100. Each gripping- device comprises a member 43, slidable along the bars 5, in which a bush 45, Fig. 4, is journaled, and the bush is clamped to a bar 6 of square cross section. Gripping-pads 51, which hold the glass tube, are carried by arms 49 pivoted on pillars 47, and the arms are connected by links 53 to levers 52 pivoted on the member 43. A spring 58 draws the levers together and forces the pads 51 to grip the glass tube. The levers 52 have lugs 54 which rest on a plate 55 having a stem that slides through the member 43. An arm 59 secured to the bush 45 raises the stem when the bar 6 is rocked and thus opens the grippers 51. The bar is rocked by a ]ever 60, Fig. 1, that rests on a cam 62 on the shaft 7, and it is moved longitudinally by means of a spring 71 and a cam 67, on the shaft 7, which swings a lever 68. This lever is linked to another lever 72 connected to a clamp 75 on the shaft 6. The lever 72 has a segmental extension 77 which co-operates with a brake member 78 adjustably secured to the bar 6. The setting of this member on the bar regulates the length of the section of tube cut off by the flame. The glass tube is gripped in the rotating chuck 100 by grippers 80, and these grippers are opened when the forked lever 83 is moved by means of a cam 86 on the shaft 7. In operation, the tube 11 is rotated by the chuck 100 and any eccentricity of rotation, or any irregularity in the surface of the tube, will result in a corresponding movement of the roller 35 and the bar 32, and therefore of the jet nozzle, 13, and the cutting flame. The angle of incidence of the flame on to the surface of the glass tube thus remains constant. The metal rollers 12, being resiliently mounted, are also enabled to follow uneven movements of the surface of the tube 11. After a length of tubing has been cut off by the flame, the chuck opens to release the tube, the jet nozzle 13 is raised and the chilling rollers 12 are lowered, the bar 7 is rocked to open the grippers 51, and the bar 6 is moved to the left in Fig. 1 carrying the grippers with it. The grippers then close on the tube and move it forwards through the chuck until the segment 77 makes contact with the member 78. The spring 88 now closes the chuck so that it grips and rotates the tube, and the jet nozzle is lowered to cut off another section of the tube.