GB600667A - Improvements in and relating to glass fabrication - Google Patents

Abstract

600,667. Glass. MacGREGOR INSTRUMENT CO. March 16, 1945, No. 6694. Convention date, Dec. 10, 1941. [Class 56] Relates to apparatus for accurately sizing, without grinding, the coacting surfaces of two glass members working one within the other, e.g. the piston and barrel of a hypodermic syringe, the rotary valve and stationary shell of a stop cock, bearings and injection nozzles for Diesel engines. As shown applied to the making of a hypodermic syringe, a length of glass tubing 32, Fig. 7, longer than the finished barrel is placed over an arbor 34, the diameter of which corresponds exactly to the required internal diameter of the barrel and, after the blank has been subjected to a preliminary heating, the lower end is constantly pressed into engagement with a shoulder 35 on the arbor by means of a weighted plunger 43. Reciprocating burners 42 positioned between three rollers 39 now traverse the blank and the rollers 39 and arbor 34 'are rotated in opposite directions. A flange 22 is formed at one end of the barrel by means of annular grooves 39<SP>1</SP> in the rollers 39 and is slabbed off at opposite edges by cutters and a perforated nose is formed at the other end by rollers, not shown. The plunger is formed somewhat similarly by the three rollers 61 and heaters 72 shown in Fig. 11. The rollers 61, which are rotated about axes at predetermined distances apart, are so shaped at one end that, acting in conjunction with an adjustable stop 68 into contact with which one end of the blank 33 supported by an arbor 60 is constantly pressed by a pressure tube 77 1 which moves from right to left, the plunger head 29 is formed. The forward end of the plunger is cut off to the required length and closed by a flame.