Patent GB-797003-A (GB)
Title: Ring cutting machine
Inventor: HOHL JOHN
IPC: B26D3/16
Filed: 1955-03-17
Abstract: 797,003. Cutting tubes transversely. OWENS-ILLINOIS GLASS CO. March 17, 1955, No. 7790/55. Class 31 (1). A machine for cutting tubes 24, e.g. of rubber or the like, into rings or gaskets 23 comprises a rotatable cutter drum 15 carrying disc cutters 48 arranged helically around the circumference thereof in two series comprising a substantially V-shape formation, each tube being mounted on a mandrel 25 which is rotated about its axis during the cutting operation. The mandrels 25 are received in pockets 27 of a stepwise rotatable carrier 26, Fig. 7, the cutter drum being rotated intermittently in alternation with the stepwise rotation of the mandrel carrier and through a complete rotation during the cutting operation. The cutters, which are freely rotatable, are mounted on the cutter drum in a plurality of right and left hand helical series S, S<SP>1</SP>, Fig. 9. The severed outer end portions of a tube 24 are ejected by means of blades 138. In a modification, Fig. 12 (not shown), the cutters are mounted in a plurality of pairs of series, each pair comprising right and left-hand series arranged in V formation and the several V's extending alternately in opposite directions circumferentially of the cutter drum. In this modification, each cutter, which is clamped in position, is angularly adjustable about its axis for bringing successive portions of the cutting edge to a cutting position. The cutter drum and mandrel carrier are rotated by means of belts and pulleys, from a shaft 19, Fig. 2, which is driven from an electric motor 16 (not shown) through the intermediary of a clutch 18 which is operated by a pneumatic motor 21 which also operates a brake 22 in relation to the shaft 19. The drive to the cutter drum also includes a speed reducer 43. At the cutting station 2 each mandrel is engaged between a spring-pressed centring pin 93, Fig. 5, on a drive spindle 28, which is driven from the shaft 19, and a second centring pin 97 which is retracted or advanced by means of a pneumatic motor 100. The mandrel carrier is indexed by means of a pawl-and-ratchet wheel, the pawl being mounted on the piston-rod of a pneumatic motor 78, and the ratchet-wheel being fixed to a table 76 rotatable about the axis of a shaft 68 which is driven from the shaft 63 of the mandrel carrier. The shaft 63 is journalled in a frame 66 which is angularly adjustable about the shaft 68, to adjust the mandrel carrier relatively to the cutter drum, by means of a manuallyoperable screw-shaft 70, the frame being locked in the adjusted position by means of bolts 72. The mandrel carrier is provided with interchangeable adapters 65 to accommodate tubes of different diameter. Cooling and lubricating liquid supplied from a pump 31 is sprayed against the cutters by means of nozzles 88. The indexing table 76 and the pneumatic motors 21, 78 and 100 are included in an electric circuit, Fig. 13, which also includes a cam disc 105 mounted on the shaft 44 of the cutter drum and having peripheral cam lugs 106, 107 and 108 which operate switches 123, 132 and 133 respectively. Switches 116, Figs. 2 and 7, located adjacent the opposite ends of the mandrel carrier, are held in the closed position at the receiving station 1 and automatically open, under the action of spring-influenced buttons 117, as the mandrel moves away from the receiving station during the indexing movement. In operation, assuming the motor 16 and pump 31 to be operating and a mandrel in position at station 1, if a switch 122, Fig. 13, is closed, the cylinder 100 is caused to withdraw the centring pin 97 and release the mandrel from the drive spindle 28 at the cutting station, the cutting of the tube having been completed. Closing of the switch 122 also operates the piston of the motor 78 to index the table 76 and the mandrel carrier so that another tube is advanced to the cutting station. As the table 76 is completing this indexing movement, a dog 126, Fig. 13, closes a switch 127 so that the cylinder 100 operates to advance the centring pin 97 and clutch the mandrel at the cutting station to the drive spindle. As the cylinder 100 is completing its movement, a dog 128 closes a switch 129. This causes the cylinder 21 to release the brake 22 and actuate the clutch 18. This connects the motor 16 (not shown) to the shaft 19 for rotating the cutter drum and the mandrel at the cutting station. The cam disc 105 makes one complete rotation before it is arrested in the position shown in Fig. 13. Just before the cam disc completes its rotation, the cam lug 107 momentarily closes the switch 132 and the cam lug 108 closes the switch 133 which causes the clutch 18 to be released and the brake 22 to be applied to the shaft 19, thereby stopping the cutter drum and mandrel driving spindle. The momentary closing of the switch 132 automatically starts a new cycle. Specification 679,988 is referred to.