Patent GB-293456-A (GB)
Title: Improvements in and relating to glass forming machines
IPC: C03B9/22
Filed: 1928-06-29
Abstract: 293,456. British Thomson-Houston Co., Ltd., (Assignees of Brown, C. A., Craig, C. W., and Vansickle, F. B.). July 8, 1927, [Convention date]. Blowing; gathering molten metal.-Relates to a rotary glass blowing machine, of the kind described in Specification 26222/11, in which a ram is projected into a furnace and gathers a charge of glass by suction, the parison thus formed being transferred to a blowing-spindle which carries it to a finishing mould. According to the invention, means are provided for cushioning the movements of the ram, for circulating cooling fluid through passages in the gathering mould and the cut-off knife, and for, retaining the ram in its inward position when the machine is out of action. The machine comprises a structure 10, Fig. 2, which rotates about a central column 12 and supports a number of blowing-spindles 11 and finishing-mould units. A bracket 13, mounted on the column 12, has a vertical hollow shaft 14, on which a swinging bracket 15 is rotatably mounted. A single ram 18 slides in guides 17 on the inclined upper surface of a carriage 16 secured to the bracket 15, and it is preferably provided with two gathering moulds which deliver parisons two at a time to pairs of blowing-spindles. The ram is rotated about the shaft 14 as it is withdrawn from the furnace, and after delivering the pansons to the spindles 15 ,it is swung back to its starting positioin in order to make a new gather. The forward end of the ram is formed as a crosshead 20 from which a pair of tubular members 21 extend, and these carry at their outer ends a pair of ram snouts 22 to which the gathering moulds 23 are attached. Each mould comprises an upper section 24, Fig. 7, secured to a head 25, and a lower section 27 carried by an arm 29 pivoted on a shaft, 28. A swinging blade 96 closes the opening 31 in the lower section through which the glass is gathered, and cuts off the excess glass after a gather is made. The lower mould section 27 is opened and closed by an air cylinder mounted on the ram head 20. The mould is moved in and out of the furnace 33, Fig. 2, by means of an air cylinder 34 which is mounted on the ram carriage 16 and has its piston 35 connected to the crosshead 20 by means of a hollow rod 36. The movements of the ram are controlled by blocks 37 mounted in the rotating structure 10 and carrying cams 38, 39. These cams move a slide 41, Fig. 3, controlling a valve 42 which regulates the supply of air to the cylinder 34. Gathering. The suction for gathering the glass is obtained by a pair of cylinders mounted on the ram carriage 16 on opposite sides of the cylinder 34. The piston rods of these cylinders are connected to the crosshead 20 so that their pistons are moved forwards when the ram is making a gather. A partial vacuum is created in the spaces behind the pistons and, at the end of the forward stroke, the spaces are automatically put into communication with the gathering-moulds, and glass is sucked into the moulds. As the moulds are withdrawn from the furnace, the blades 96 shear off the excess glass, and the moulds are then opened and the parisons are dropped on to the blowing- spindles 15. While a gather is being made, the ram carriage is turning about the shaft 14. This movement is effected by dogs 83 on the rotating frame 10 which engage a, bar 85, slidable in guides on the underside of the bracket 15, and force the bracket to rotate against the pressure of air in a cylinder 86, Fig. 3, mounted on the bracket 13. The bar 85 is drawn inwards at the proper time by a cam 176 fixed on the bracket 13, and the compressed air in the cylinder 86 thereupon swings the ram carriage back to its initial position. The movements of the ram are cushioned by means of a cylinder 89 having its piston 90 connected with the crosshead 20 by a rod 91. The movement of the ram compresses air in one end or the other of the cylinder, and this pressure is relieved by a series of adjustable vent cocks. The reciprocation of the ram can be stopped at any time by means of a solenoid' 180 which operates a locking-lever 189 that engages a slot 191 formed on the underside of the ram. When the machine is in operation, the current supplied to the driving motor also passes through the solenoid 180 which withdraws the lever 189 against the action of a spring 193. When the current supply is interrupted, the spring 193 causes the lever 189 to hold the ram in its retracted position. This prevents the ram from returning to the furnace and being damaged by heat. The circuit of the solenoid may be broken at will by a switch if it is desired to hold the ram out of action while the machine is still rotating. Cooling moulds. The mould sections, shearing blades, and those portion of the ram carriage nearest the furnace, are cooled by water which is circulated from a pipe 119, Fig. 7, through passages 120, 121 in the upper mould section. The water also passes through passage 136 in the shearing-blade, through a chamber 150 in the lower mould section, and through a chamber 160, Fig. 2, in the nose of the ram.