Patent GB-469585-A (GB)
Title: Improvements in or relating to machines for shaping the ends of glass receptacles and tubes
IPC: C03B23/09
Filed: 1936-12-11
Abstract: 469,585. Glass manufacture. DICHTER, J. Dec. 11, 1936, No. 34114. Convention date. Dec. 11, 1935. [Class 56] Relates to a machine for forming a screw thread within the mouth portion of a glass receptacle or tube, the machine being of the kind in which a series of horizontally disposed tubes are moved in succession through a number of operating stations including a thread-forming mandrel which is introduced into the neck of each tube in turn. According to the invention, means are provided for moving the mandrel axially away from a tube, or vice versa, after the thread-forming operation, in order to permit the tube to be moved laterally away from the mandrel. A glass tube 14, Fig. 1, is placed by hand or by known mechanical devices, on pairs of wheels 3, and a roller 12 presses on, and assists in rotating the tube. The roller 12 is raised and lowered, to permit the removal of the tube 14, by a vertical rod 111 which is raised by a lifting-bar 19. One end of the tube rests against an adjustable abutment 15 while the other end is heated by suitable burners in the usual way. A screw-threaded mandrel 39 is inserted in the softened end of the tube while the outer surface of the glass is gripped and shaped by rollers 28, 28<1> disposed vertically above and below the tube. These rollers are adjustably mounted on carriers 27, 271 carried by vertical sliding rack-bars 25, 251 which are geared together by a pinion 29, so that the rollers are moved to and from the glass tube when the bar 25 is raised or lowered by a cam 35 on the driving shaft 34. The mandrel 39 is fitted to one end of a rod 54 journalled in a sleeve 53 which is slidably mounted on a block 5 and is kept in position by a spring 57. The block is reciprocated along an horizontal guide rod 40 by a cam 68 on the shaft 34. The other end of the rod 54 is fitted with a ratchet wheel 58 the teeth of which are engaged by a pawl 59, Fig. 2, secured to a vertical spindle 116. This spindle is journalled in the block 51 and is rotated when a lever 60, Fig. 1, secured to its lower end, strikes a stationary part of the mechanism at the inward limit of the movement of the block 51. In operation, the inward movement of the block 51 inserts the mandrel 39 in the softened end of the rotating glass tube 14, and at the end of the movement, the lever 60 rocks the pawl 59 and releases the ratchet wheel 58 so that the mandrel can rotate freely with the glass tube. At the same time, the rollers 28 28<1> grip the softened glass and shape it against the mandrel. The block 51 then moves outwards, the ratchet 58 becomes locked by the pawl 59, and the mandrel screws out of the glass tube, the spring 57 permitting smooth relative movement between the mandrel and the tube. The travel of the block 51 is arranged to draw the mandrel clear of the end of the glass tube, and the rollers 28, 28<1> move apart to permit the tube to be replaced by another. In a modified construction, the roller 12 is inclined to the axis of the glass tube 14, so that it presses the tube against the abutment 15. In this case, the abutment is moved by a cam away from the end of the tube, so that the pressure of the roller unscrews the tube from the mandrel. In another modification, the tube may be held in a chuck which may be moved in the direction of the axis of the tube to withdraw the tube from the mandrel. Alternatively, the rotation of the chuck may be stopped and the mandrel then rotated and moved to withdraw it from the tube. The mandrel and the rollers 28, 281 may also be operated manually.