Patent GB-600741-A (GB)
Title: Machine for fabricating glass
IPC: C03B23/055
Filed: 1945-02-06
Abstract: 600,741. Glass manufacture. MAcGREGOR INSTRUMENT CO. Feb. 6, 1945, No. 2976. Convention date, May 7, 1942. [Class 56] Relates to a machine for making from glass tubing shaped articles of uniform internal diameter and capacity such as hypodermic syringe barrels, comprising a number of arbors 5, Fig. 3, carrying the tubular glass blanks and rotatably mounted in a ring upon a turret 4 which is intermittently rotated so that each arbor advances from an idle station A, Fig. 1, to a loading station B, through intermediate stations C ... 0 to an unloading station P, the turret being stationary whilst the arbors are at the stations. The blanks are preheated at stations C and D ; at station E the blanks are sized to arbor dimension and a flange is formed at the lower end of the blank ; at station F, the apertured tip for receiving the needle is formed, the opposite edges of the flange are slabbed off and the excess glass at the tip is cut off, and stations G ... O are idle stations. The arbors 5 are rotated about their own axes by a constantly running belt 14, Fig. 3, driven by an electric motor 19 and the turret is rotated step-by-step by a second motor continuously driving a vertical shaft 37 through belts 23, 27 and worm gear 29a, b, c, 36. The shaft 37 carries a drum 51 having a number of cams 52 and also drives a shaft 44 through gears 50, 49, 48, the shaft 44 carrying at its lower end a gear-wheel 43 having two teeth only which, through a pinion 41, intermittently drives a gear-wheel 40 on the hub 39 of the turret. The arbors 7 are provided with notched discs 9, Fig. 1, whereby they may be held against rotation at certain stations ; the turret is also locked against rotation whilst the arbors are at the stations by means of pins 70 projecting downwardly from the turret adjacent each arbor and engaging a socket 69, Fig. 3, in a retractible rod 67 reciprocated in timed relationship with the movement of the turret. Backlash of the turret, due to the belt 14, is prevented by a pivoted notched finger 77, Fig. 1, engaging one of the pins 70. After passing through stations C and D, where the blanks are heated along their length by burners, not shown, the blanks reach station E, Fig. 6, which comprises three rollers 83 gripping the blank between them and, by frictional contact with the rotating blank, themselves rotating about their own axes. The rollers are journalled in pivoted plates 99 which are spring biassed normally to press the rollers into contact with the blank, but which are swung about their pivots to free the rollers from the blank as the latter approaches and leaves the station E. Movement of the plates 99 is effected by piston and cylinder mechanism and the valves controlling the supply of fluid pressure thereto are actuated by two of the cams 52. Whilst at station E, the blank is heated by burners 61 reciprocated by a cam 56 on the gear-wheel 48, Fig. 3, and a pressure pad 84, acted on by a weight 106, is lowered into contact with the upper end of the blank. Upward movement of the pressure pad is controlled by another piston and cylinder mechanism actuated by another cam 52. Another cam 52 controls a piston and cylinder mechanism 73 releasing the locking rod 67 against the action of a spring 76. The blanks are accurately shrunk at station E to the diameter of their supporting arbors 5 and a flange S is formed at the lower end of the blanks resting on the top of an enlarged portion 7 of the arbor by an annular groove 116, Fig. 6, in each roller 83. At station F, Fig. 8, a tipbore forming rod 87 is depressed by a spring when fluid-pressure in another piston and cylinder mechanism is released under the control of a fifth cam 52, thereby forming an axial aperture through the globule of glass at the top of the partially formed barrel. Rollers 85 for shaping the exterior of the tip are swung out of the path of the blank, as it approaches and leaves station F, by fluid pressure under the control of a sixth cam 52, and when the rollers are in contact with the tip, the latter is continuously heated by burners, not shown. The opposite edges of the flange S are slabbed off by means of cutters 88, 89 which are reciprocated vertically by means of another piston and cylinder mechanism controlled by a seventh cam 52, and the flange is continuously heated to fire-polish the cut edges. During the cutting of the flange, the arbor 5 carrying the blank at station E is held stationary by means of lug entering one of the notches in the disc 9 on the arbor, the lug being associated with the piston and cylinder mechanism operating the cutters 88, 89. The eighth cam 52 operates a piston and cylinder mechanism 185 for swinging a cutter 92 to cut off the globule of excess glass 91 adjacent the formed tip of the barrel.