Patent GB-745053-A (GB)
Title: An improved machine for manufacturing metal containers
IPC: B21D22/16
Filed: 1952-11-01
Abstract: 745,053. Making containers. RAWLE, T. G. Jan. 22, 1954 [Nov. 1, 1952], No. 27549/52. Classes 83 (2) and 83 (4). Spinning.-A machine for manufacturing metal containers, e.g. buckets and open-top kegs of the kind in which a workpiece of metal or metal alloy is rotated and formed over a rotating former or chuck by stretcher tool means passed at pressure over the workpiece along guide means is characterized in that the stretcher tool means are fed by fluid pressure means. The machine comprises a rectangular frame 1 the vertical members 2 of which constitute guides for a reciprocable table 3 supported by pads 4 attached to pneumatic pistons 6. The upper member 1b of the frame carries a headstock 8 in which is mounted a belt-driven spindle 9 carrying a face plate 13 to which is secured a former 14 provided at its lower end with a spring ejector 15. The lower member 1a of the frame carries the cylinder 7 for the pistons 6 and also a gripper cylinder 16 the piston 17 of which carries a gripper 18a. A spigot 18b on the gripper engages a corresponding bore in the ejector 15 to ensure correct alignment. The table 3 carries four or more radially arranged and equally spaced angularly adjustable base guides 19 on each of which is slidably mounted a carriage 20 carrying an adjustable stretcher tool 21. The tool is adjusted by means of a screw-threaded spindle 22 engaging in a nut 20a fixed to the carriage 20, a pawl 23 engaging a ratchet wheel 24 on the spindle 22 the pawl being rockable by a cam 25 on the outer end of the guide 19 when the tool is forced outwards at the end of the working stroke. Each carriage 20 is attached to a pneumatic piston 27 operable within the base guide 19. The gripper 18a is controlled by a two-way pedal-operated valve 30 connected to the main air supply line 31 and the feed pistons 6 by a common two-way valve 34 via speed control valves 35. The tool cylinders in the guides 19 are connected to a common blow-off and regulating valve 37 and are controlled by a common two-way valve 39. In operation, a metal disc 40 is placed over the spigot 18b, the valve 30 is operated to cause the gripper to press the disc against the ejector 15 of the former which is now rotated by a motor 12. The valve 39 is operated to press the tools against the disc and the valve 34 is opened to raise the table 3 upwards and so cause the tools to shape the disc around the former. The blow-off valve 37 enables the tool heads to retract during their upward stroke and at the same time exert sufficient pressure against the former. At the end of the forming stroke the pawls 23 abut against cam stops 25 and are rocked to turn the ratchet wheels 24 to advance the tools to take up wear. Finally, the power is arrested, the table lowered and the gripper retracted and the formed core ejected by the ejector 15. For making a stepped neck for a container, the narrow end of the former is correspondingly stepped and the valve 39 is operated to retract the tool heads as they encounter each horizontal part on the stepped portion of the former. When making flat-topped containers in one stroke a stop disc of the same diameter as the former is placed between the gripper and the former and the tools abut against this disc prior to the feeding operation.