Patent GB-794732-A (GB)
Title: Improvements in or relating to clutch mechanisms for imparting step-by-step movement
IPC: F16D11/04
Filed: 1955-03-11
Abstract: 794,732. Gearing for stopping and starting machinery; positive clutches. ERICSSON BROS., Ltd., SIMPSON, A. W., and DAVIES, R. D. March 12, 1956 [March 11, 1955; Nov. 29, 1955], Nos. 7271/55 and 34191/55. Class 80 (2). Clutch mechanism for alternately imparting step-by-step movement from a driving clutch member to two driven clutch members coaxial with the driving clutch member, comprises sets of slidable clutch dogs providing a driving connection between the clutch members, and operating means for selectively engaging the clutch dogs. The mechanism described drives from a single source of power through two clutches which drive the paper feed mechanism and the guillotine mechanism in a printing machine. In one form, a cylindrical driving clutch member 1, Figs. 1, 4, carries a pair of oppositely disposed clutch dogs 13, 14 biased by springs 27 to engage their truncated conical ends in two similarly shaped recesses 29, 30 in driven clutch members 6, 7. The clutch member 6 is fast on a shaft 5 which drives the paper feed mechanism, and the clutch member 7 is fast with a sleeve 9 which drives the guillotine. Each dog 13, 14 is provided with an inclined cam slot 19, 20, which can be engaged by a roller 34, 35, respectively, on levers 15, 16 turning about a shaft 33, Fig. 3, and normally biased by gravity to hold the rollers clear of the dogs, &c. Engagement of one of the rollers 34, 35 with its associated cam slot, when the driving clutch member 1 rotates, causes the appropriate dog to be withdrawn from its corresponding hole in the driven clutch member 6 or 7. Flanges 47, 48 on the two driven clutch members are each formed with a single V-notch 46, Fig. 3, which can be engaged by a detent roller 43, 43a projecting sideways from a lever 45 spring-biased to engage the roller in the notch. When the clutches are engaged, the detent rollers 43, 43a ride out of their notches, but disengagement of one of the clutches by operation of the lever 15 or 16 to withdraw the associated dog occurs at such a position that the driven clutch member 6 or 7 is then held by its roller 43, &c. Continued rotation of the driving clutch member 1 after disengagement of one of the clutches disengages the cam slot 19 &c. in the clutch dog from the roller 34 or 35 on the lever 15 or 16, and the flat end of the clutch dog then slides over the corresponding flat surface of the driven clutch member 6 or 7 until it completes a revolution and once more reaches a position opposite to the recess 29 or 30. If the lever 15 or 16 has been allowed to fall so that the roller 34 &c. does not enter the cam slot 20, the dog 13 or 14 is slidden axially by its spring 27 to re-engage the clutch and, as the driven member 6 or 7 moves off, the detent roller 43 or 43a rides out of its V-notch 46. If, however, the lever 15 or 16 is maintained in its raised position, the roller 34 or 35 again enters the cam slot in its associated dog and the clutch is maintained disengaged. The two clutches can be simultaneously disengaged by allowing a spring 39, Fig. 7, to turn a shaft 38 fast on which are two arms 37 engaging the undersides of the levers 15, 16 to move them upwards to engage their rollers 35 &c. in the appropriate slots in the clutch dogs. Tension applied manually to a tie-rod 51 allows the levers 15, 16 to fall and the clutches to engage. Clutch control mechanism is provided so that the two clutches are engaged and disengaged in a predetermined sequence. The driving clutch cylinder 1 includes at its centre a gear 1a meshed by a gear 55 fast on an input shaft 54. The two gears 1a, 55 are so proportioned that the ratio between them is 2: 1. Two axially directed arms 58, 59 are positioned at opposite sides of the gear 55 and diametrically opposite each other. The ends of the two arms carry rollers 60, 61 which alternately slide up under the levers 15, 16 and lift them to a position in which they cause disengagement of the paper feed and guillotine clutches 6, 7. As shown in Fig.1 the arm 59 &c. has raised the lever 16 and the guillotine clutch 7 is in process of disengaging. A half-revolution of the shaft 54 causes a complete revolution of the gear 1a, &c., during which time the paper feed clutch 6 is engaged. At the end of this period, the arm 58 &c. disengages the paper feed clutch, the driven member of which is stationed by its detent roller 43 and V-notch 46, and the guillotine clutch re-engages. A further half-revolution of the gear 55 drives the guillotine clutch through one revolution, and the position shown in Fig. 1 is again restored, the paper feed clutch reengaging and the lever 16 rising to disengage the guillotine clutch. The roller 43a then slides into the V-notch in the flange 48 to hold the driven member 7 of the guillotine clutch stationary. An additional control is provided so that the guillotine clutch is held disengaged every other time that the mechanism so far described would allow it to engage. An eccentric 72, Figs. 1, 2, fast on the shaft 5 driving the paper feed mechanism, is engaged by a cam follower 71 on a lever 70, the other end of which carries a pawl 69 engaging a twelve-toothed ratchet gear 68 fast on a shaft 67. Each revolution of the shaft 5 thus advances the ratchet wheel 68 &c. by one step. Fast on the shaft 7 is a six-lobed cam wheel 64, Figs. 1, 3, which cooperates with a roller 63 on an arm extending rightwards in Fig. 1 from the lever 16. When a lobe on the cam wheel 64 lies beneath the roller 63, the arm 16 is maintained in its raised position and the guillotine clutch cannot disengage, irrespective of the position of the arm 59 &c. When a recess between two of the lobes of the cam wheel 64 lies beneath the roller 63, then, provided the arm 59 on the wheel 55 is not in the position shown in Fig. 1 but is at the diametrically opposite side of the axis of the driving shaft 54, the lever 16 can fall to allow the guillotine clutch to engage. The sequence of operations now is that for the first three revolutions of the driving clutch member 1, the paper feed clutch 6 is engaged, then disengaged, and then re-engaged. During these three revolutions the guillotine clutch 7 is disengaged. For the fourth revolution of the driving clutch member, the paper feed clutch is disengaged and the guillotine clutch engaged. The cycle is then repeated. The mechanism is partly immersed in an oil bath and the clutch cylinder 1 co-operates with a scraper blade 80, Fig. 1, which directs the oil to the clutch parts. In a modified construction, a driving sprocket 91, Figs. 9, 10, 12, is formed with arcuate slots 92 which can be engaged by an axially slidable spring-biased dog 97 in a cylindrical driven clutch member 85 and by a similar dog 98 in a cylindrical driven clutch member 87. The clutch member 85 is fast with a shaft 81 connected to the guillotine mechanism in an addressing or like machine, and the clutch member 87 is fast with a shaft 89 driving the paper feed mechanism. Slots 95, 96 in the clutch members 85, 87 receive radially projecting cams 101, 102 on the clutch dogs 97, 98. Diametrically opposite to the dogs 97, 98, the driven clutch members contain detent balls 107, 108 spring-biased to engage holes 111 in stationary plates 82, 83 supporting the mechanism. The cam dogs 101, 102 co-operate with tongues 114a projecting downwardly from arms 114, 115 on an oscillating control member 113 pivoted about an axis 116. The arms 114, 115 project through slots 119 in a plate 117 on top of the mechanism, the slots limiting the angle through which the member 113 can turn. In the position shown in Figs. 9, 10, the driven part 85 of the guillotine clutch is held stationary by its ball detent 107, and the cam 101 engages the tongue on the arm 114 to hold the dog 97 disengaged from the slots 92 in the driving clutch member 91. The paper feed clutch is engaged, and its driven member 87 turns with the driving clutch member 91. Just before the completion of a revolution, the cam 102 on the clutch dog 98 engages the tongue on the arm 115 and turns the operating member 113 clockwise as seen in Fig. 9, thus releasing the tongue on the arm 114 from the cam 101 on the dog 97. The dog 97 is then moved by its spring into the arcuate recess 92 opposite to which it is positioned, and the guillotine clutch is engaged. As the driving clutch member 91 continues to rotate, the cam 102 rides up the tongue on the arm 115 and thus withdraws the dog 98 from the arcuate recess 92 to disengage the paper feed clutch. At the completion of another revolution, the cycle is repeated, the operating member 113 turning anti-clockwise back to the position shown in Fig. 9, the paper feed clutch re-engaging and the guillotine clutch disengaging. The ball detents 107 may be replaced by means adjustable about the axis of the clutch mechanism so that the driven clutch members can be stationed in any desired position. As a modification, the operating member 113 is dispensed with and the cams 101, 102 on the clutch dogs are arranged to actuate switches in the circuits of electromagnets which are energized to cause operating means to be projected into and withdrawn from the paths of the cams, to withdraw the clutch dogs from their engaged position. Specification 649,199, [Group XVI], is referred to.