Patent GB-1228477-A (GB)
IPC: B23D36/00
Filed: 1968-07-04
Abstract: 1,228,477. Flying shears and punches. WILHELMSBURGER MASCHINENFABRIK HINRICHS & SOHN. 4 July, 1968 [6 July, 1967], No. 31908/68. Heading B3W. [Also in Division F2]  In apparatus controlling the movement of a flying carriage 20 carrying a punch or, as shown, a shear tool 50 arranged to punch or cut a travelling strip 42 at predetermined intervals of adjustable constant length, a rack 19 acting on the carriage 20 is driven by a strip-feed roller drive motor M through twin transmissions interconnected by a bevel differential 7 and respectively incorporating pneumatically or electromagnetically actuated clutches 5, 5<SP>1</SP> alternately engageable to initiate drive of the differential cage 7<SP>1</SP> which is geared to the rack 19. A live roller 2 driven by the motor M is connectible to screw shafts 6, 6<SP>1</SP> respectively through gears 3, 4 and the clutch 5, and gears 3<SP>1</SP> ,  41 and the clutch 5<SP>1</SP>. The shafts 6, 6<SP>1</SP> are fast with discs 13, 13<SP>1</SP> having dogs 16, 16<SP>1</SP> engageable with dogs 17, 17<SP>1</SP>. The discs 13, 13<SP>1</SP> are fast with side wheels 8, 8<SP>1</SP> of the differential 7. The dogs 17, 17<SP>1</SP> are provided on nuts 11, 11<SP>1</SP> engaging the screw shafts 6, 61 and sliding on rods 12, 121 respectively fast on and circumferentially adjustable, by way of an annularly slotted ring 14, with respect to, the cage 7<SP>1</SP>. To provide gentle carriage acceleration, the rack 19 has pivoted thereto a member 24, which, in operation, initially bears against an abutment face 25 and when the rack 19 begins to advance, slides on the carriage rear wall until the full rack thrust is transmitted to the carriage. The carriage is returned by a pneumatic or hydraulic actuator or, as shown, a spring 40.  In operation, assuming the clutches 5<SP>1</SP>, 5 to be respectively engaged and disengaged, the screw shaft 6<SP>1</SP> is driven and drives, reversely, through the stationary differential, the screw shaft 6. In consequence, the nuts 11<SP>1</SP>, 11 are both traversed leftwards until the dogs 17<SP>1</SP>, 16<SP>1</SP> engage, whereupon the differential is solidly driven and the cage T<SP>1</SP> drives the rack 19. As soon as the rack moves, a switch 43 is opened to effect engagement of the clutch 5. As soon as the carriage speed equals that of the rack, operation of the tool 50 is brought about, as by a switch 51 on the carriage. Upon completion of its operation, the tool 50 generates a signal or opens a switch to disengage the clutch 5<SP>1</SP>, whereupon the spring 40 is able to apply a return thrust to the carriage and rack. Since the clutch 5 remains engaged the dogs 16<SP>1</SP>, 17<SP>1</SP> are disengaged and the nuts are traversed rightwards until the dogs 17, 16 engage and fresh advance of the rack 19 is initiated. This time, as soon as the rack moves, the switch 43 effects re-engagement of the clutch 5<SP>1</SP> and the complation of operation of the tool 50 effects disengagement of the clutch 5, the relevant switches having alternating roles. The adjustment of the length intervals of the punching or cutting is effected by circumferential adjustment of the ring 14 to alter the distance between the nuts 11, 11<SP>1</SP> and hence the interval taken for the nuts to traverse the screw shafts.