Patent GB-861592-A (GB)
Title: Improvements in or relating to automatic devices for producing longitudinal step-by-step advancement then transverse movement and then longitudinal step-by-step retreat,of one element relative to another
IPC: B29D19/04
Filed: 1957-07-18
Abstract: 861,592. Drilling-machine details; quincuux and like staggered feeds. GIUSI, G. July 18, 1957 [July 18, 1956], No. 22859/57. Classes 83 (3) and 83 (4). In a machine in which an element is fed in steps, the element, e.g. the work-table in a button-making machine for cutting discs from sheet material, is advanced in steps, then moved transversely, and then retreated in steps, the first retreatstep being equal to only half of the normal step so that the buttons &c. may be cut in closely spaced staggered rows, e.g. by a hollow punch or a drill (not shown). The cutter is fed by a cam 3 on a cam shaft 2 driven by a motor (not shown) through a worm-wheel 1. The shaft 2 also supports a cam 25 effecting the transverse movement, and the driving member 4 of a Geneva wheel 5, which drives intermittently a table-feed. pinion 16 through a reversing gear 7-13 and dog clutches on opposite ends of the sleeve 13. A cam 17 controls movement of cam 25 along the cam shaft. A shaft 6 supports the wheel 5, which is formed with teeth 7 driving a gear 9 loose on the pinion shaft 11 and the gear 8 meshing with the gear 12 driving the gear 10, also loose on the shaft 11 but driven in the opposite sense to gear 9. A pair of diametrically opposite clutch teeth 14, Fig. 4, with adjacent recesses 15, is formed on each end of the slidable sleeve 13 keyed to the shaft 11, and co-operating teeth and recesses are formed on the driving gears 9, 10. A forked lever 37 on a pivot 35, Fig. 3, shifts the sleeve 31 under the control of a lever 42 on a pivot 43 and operated by dogs 41 on the table. A spring 44, attached to a part of the machine casing A in line with the pivots 35, 42, and to one end of the lever 42, biases the lever against one of the limbs 36 of the lever 37, and ensures rapid movement of the lever and thus of the sleeve 13 beyond the deadcentre position. Movement of the lever 37 is also influenced by a further lever.32 on the pivot 35, and between the inturned end of lever 32 and the limbs 36 are springs 38. Stops 39 on the limbs restrict relative movement between the levers 32, 37, and the opposite end 34 of the lever 32 co-operates with the end of a lever 18, Fig. 2, as described below. One end of the lever 18 is pivoted at 19 to a member 20, normally held against axial movement by a stiff spring 21, and the end 22 influenced by a less stiff spring 23. The rod 20 is pivoted to one arm 28 of a bell crank 29, the other forked arm 30 of which embraces the hub of cam 25, which is influenced by a spring 27. Operation.-While the table is being advanced in the direction R, the parts are positioned as depicted in Fig. 3. When the table is close to the end of its movement, the dog 41 rocks the lever 42, which strikes the other limb 36, but is prevented from moving the sleeve 13 into engagement with the gear 9 and thus reversing the feed, by engagement between the stop 39 and lever 32, which is prevented from rotating by the side of the end 22 of lever 18, which is in the position depicted in broken lines. Thus interruption of the feed while the gears 9, 10 are rotating is prevented. When the cam 17 permits the lever 18 to return to the full-line position depicted in Fig. 3, the ends of the teeth on the sleeve are moved against the gear 9, in which the corresponding notches are out of alignment by an amount sufficient to permit the gear to rotate by an amount equivalent to half of a normal feed step before the teeth enter the notches and engage the reverse feed. While the teeth are disengaged, the end 34 of lever 32 engages the end 22 of lever 18, which is thus caused, by cam 17, to rock about the end 22 and operate the rod 20 against the influence of the spring 21. This rocks the lever 29 and moves cam 25 into engagement with its follower 24, which operates the transverse feed mechanism (not shown) while the wheel 5 is being rotated. Projections 45 on the end 22 prevent escape of the lever 32, should the clutch teeth enter their recesses before the transverse movement has finished, the lever 32 moving out of the path of movement of the end 22 when the transverse movement has finished. The shaft 6 is rotated intermittently through one quarter, and the shaft 11 through one half of a revolution, for each rotation of the shaft 2. In order to compensate for backlash, wheel 5 is mounted adjustably on the shaft 6.