Patent GB-704725-A (GB)
Title: Improvements in or relating to a paper web cutting device
IPC: B26D3/08
Filed: 1952-05-09
Abstract: 704,725. Cutting machines. BLACKCLAWSON CO. May 9, 1952 [May 14, 1951], No. 11766/52. Class 31 (1) A cutter for a travelling paper web 12 comprises a carriage 28 movable transversely of the direction of travel of the web, a knife 42 mounted on the carriage for movement between a retracted position out of the path of the web and a projected position in which it penetrates the web, and means for effecting this movement of the knife on the carriage in timed relation to the transverse movement of the carriage so that the knife is caused to penetrate the web and. thereafter to travel with the carriage transversely of the web in cutting relation with the latter. The invention is described as applied to the cutting of a web transversely for the purpose of transferring delivery from one reel 126, Fig. 1, to another reel 128, The carriage 28 is movable across the machine beneath the web 12 in a track formed by a slotted tube 16 carried by a second tube 18 on adjustable uprights 20, 22. The carriage comprises a base 26 slidable within the tube 16 and having a central upright 38, on the top of which a bracket 52 carrying the cutter blade 42 is mounted for vertical reciprocation by pivoted links 66, 68. Actuation of the links is effected by a driven endless-chain 74 which also moves the carriage across the machine ; the chain passes over sprockets 72, 78 at the ends of the tubes 16, 18 and sprockets 36, 80 on the carriage and is connected to the link 68. The cutter blade 42 is adjustably mounted in an upwardlyinclined slot 44, Fig. 6, in a plate 46 which is itself mounted on a vertical pivot 60 on the bracket 52, being normally maintained in a direction longitudinal of the sheet 12 by a co-operating spring 54 and screwed stop 56. When in operation it is desired to transfer delivery of the web 12 from the reel 126 to the reel 128, the depression of a push-button energizes the drive motor of the chain 74 so that the latter straightens the links 66, 68 and causes the blade 42 to pierce the web which in its movement effects cutting of a narrow longitudinal strip 148 ; when the links lie flat against the upright 38, the motor is automatically de-energized (if it has not previously been de-energized because the operator has released the push-button) so that the carriage itself does not move at this stage. The operator then tears the strip 148 across, winds it on the reel 128, and depresses a further push button to energize the motor and cause the carriage to move transversely across the web and cut it completely along an inclined line ; the pivotal mounting of the plate 46 enables the knife to take up the correct angular position for this cut. At the end of this movement, a limit switch is automatically opened by the carriage to de-energize' the motor, but the momentum of the carriage carries it on sufficiently to close a second switch to energize the motor in reverse for the return of the carriage. When the carriage reaches its initial position a limit switch automatically stops the motor. A hand-operated switch may be set so as to provide for the stopping of the carriage at the end of its forward movement. The carriage 28 is enclosed by a casing 86.