GB567693A - Improvements in or relating to intermittent gear drives for printing and other machines - Google Patents

Abstract

567,693. Intermittent toothed gearing. JONES. K. W. Aug. 16, 1943, Nos. 13259/43 and 8898/44. [Class 80 (i)] Consists in intermittent toothed gearing in which the driven gear is at all times in mesh with gearing deriving movement from the driving shaft to ensure that the driven gear will be correctly positioned for the leading tooth of the driving gear to re-engage therewith, thus enabling the gearing to be run at high speeds. The driving shaft 1, Fig. 1, carries a mutilated gear 3 adapted to drive a gear 4 on the output shaft 2. Associated with the gear 4 are two diametrically opposed segment gears 5, 6 on arms 7, 8 mounted on a shaft 10, fast with which is a cam plate 19 having slots 15-18 adapted to be engaged by rollers 13. 14 on arms 11, 12 on the shaft 1. In practice, the wheels and cam plate would be more compactly arranged than is shown in Fig. 1, e.g. the wheel 104 engaged by the segments would be at the side of gear 4 so as to constitute, in effect, a single gear. Assuming the gearing to be running and the driving gear 3 to have just run out of engagement with the gear 4 and the latter to be at rest, the segment gear 5 will have been brought into engagement with the wheel 104 by the cam plate, and the roller 13, i.e. the run-out roller will be about to leave the slot 15 thereby bringing the cam plate, Segment gear and driven gear 4 to rest. After a predetermined movement the roller 14, i.e. the run-in roller, enters the slot 16 and rotates the segment 5 and gear 4 which, by the time the gear 3 is again about to engage it, is running at the same speed as and is in the correct position to engage, the gear 3. As the gears 3 and 4 become meshed, the segment 5 leaves the wheel 104 and the run-in roller 14 leaves the slot 16, thus leaving the shaft 10 and gear 4 at rest until the roller 13 enters the slot 17 to rotate the shaft 10. When the speed of the segment 6 reaches that of the gear 4, it will be brought into mesh with wheel 104, whereupon the trailing tooth of the gear 3 runs out of engagement with the gear 4. The roller 13 then leaves the slot 17 and the shaft 10 will again be at rest. The number of teeth in the gear 3 may be changed by forming the gear of the toothed discs 103, 203 and rotating them relatively to one another to " fan out " the teeth, after which they are secured by a bolt. To correspond with such an adjustment, the arms 11, 12 are also adjusted through their being mounted on shaft 1 and sleeve 20 integral respectively with discs 203 and 103. The shape and the number of cam slots employed may be varied. The seg. ment gears may be externally toothed, in which case intermediate gearing would be necessary to preserve the correct direction of rotation of the driven gear 4.. In a modification, the acceleration and deceleration of the driven gear, and the brief periods of constant speed when not engaged with the gear 3, may be obtained by the means shown in Fig. 3. A multi-mutilated gear 23 on the layshaft 10. co-operates with a gear 24 on the shaft 1, and the slots 150-180 in plate 190 have straight radial open end portions, and enlargements 151-181 in which the rollers may move freely when the gears 23, 24 are in mesh. In further modification, Fig. 4, the constant speed of the driven member may be obtained by providing the cam plate 19 with straight radial slots 150-180, the rollers 13, 14 being carried by members 110, 120 pivotally mounted at the ends of arms 11, 12 on the shaft 1, additional rollers 130, 140 coaxial with these engaging a cam track 25 in a fixed cam plate 26. As a further modification, a star member on the layshaft may carry a driving roller at the end of each of its arms to engage a cam slot in a disc on the driving shaft. Means may be provided for looking the driving plate or star-wheel when disengaged from the driving means.