Patent GB-1307735-A (GB)
Title: Bottles and the method and apparatus for forming them
IPC: B67B5/00
Filed: 1970-05-22
Abstract: 1307735 Blow moulding AUTOMATIC LIQUID PACKAGING Inc 22 May 1970 [28 May 1969] 24939/70 Heading B5A [Also in Division B8] A blow-moulded and filled thermoplastics bottle 30 is formed with an integral replaceable closure or cap 32 joined to the bottle neck by a weakened portion 65 so that the closure or cap may be twisted off or cut from the neck and subsequently refastened thereto. The bottle may be blown from a parison of polypropylene, low or high density polyethylene, polycarbonate acetate or ABS in a mould by a blowing and filling tube 22 comprising on an axially adjustable mandrel 54 threaded on a filling spout 50. The mould comprises bottle body mould halves 14a, 14b, neck and lower cap-forming mould halves 35a, 35b affixed to the body mould halves, and relatively slidable upper cap-forming mould halves 40a, 40b, which are adapted to close and complete the cap formation to seal the bottle after the bottle has been -blown filled, and the tube 22 removed. The mould halves 35a, 35b include mould parts 39a, 39b having flat mould faces 41b which co-operate with an axial pointed extension 62 at the end of the mandrel to form a weakening groove 64 in the cap/neck junction portion 65. The axial adjustability of the mandrel on the spout permits the depth of the groove to be varied. Further mould parts 37a, 37b are profiled to form a groove 33 in the bottle neck to permit snap fastening reattachment of the cap after it has been initially twisted off the neck. Vacuum passages are provided in the neck and cap mould ports to assist neck and cap formation. In a modification, Figs. 12-18 (not shown), the bottle neck is moulded with threads 73 adapted to be engaged by the cap/neck junction portion or flange 65. A weakening groove 74 is formed externally of the bottle by providing the pointed projection 85 on the mould parts instead of the mandrel. In a further embodiment, Fig. 24 (not shown), both the mould and mandrel are provided with pointed projections. In other embodiments, Figs. 19-23 (not shown), a threaded bottle neck is moulded with an integral threaded stopper using mould parts 104, 165, 106 and a plate 165 (125), which cooperates with a tapered mandrel portion 118 (126) to form a weakening groove 116 at the junction of the stopper and neck. In a further embodiment, Figs. 25-28 (not shown), the mandrel and neck and cap mould halves are formed with flanges 142 and recesses 140 respectively to form interengageable quarter threads on the neck and cap. In a similar embodiment, Figs. 29-33 (not shown), to avoid damage to the quarter threads of the cap on retraction of the mandrel and filling spout assembly 160, the end of the mandrel which co-operates with a plate 165 to form the weakened cap/neck junction flange is formed with flexible tongues 167. An upward movement of a surrounding pneumatically-operated-cam sleeve 174, the tongues are urged inwardly and clear the cap thread formation on retraction of the assembly 160. In a final embodiment, Fig. 34 (not shown), damage to the -cap threads is minimized by arranging the -mandrel axially offset with respect to the bottle neck axis.