Patent GB-496719-A (GB)
Title: Improvements in and relating to mechanism for feeding tobacco leaves to leaf stemming machine
IPC: A24B5/00
Filed: 1937-06-01
Abstract: 496,719. Tobacco-stemming machines. INTERNATIONAL CIGAR MACHINERY CO. June 1, 1937, No. 15177. Convention date, Dec. 23, 1936. [Class 130] In a mechanism for feeding tobacco leaves to a stemming machine, in which the leaves are advanced in spaced relation and are transferred at regular intervals to the machine, a control device is arranged to permit continued operation of the advancing mechanism so long as the desired spacing is maintained and to stop the advancing mechanism when leaves having less than the desired spacing are brought to the delivery end of the advancing mechanism. The leaves are placed across belts 11, 12 with their butt ends aligned by means of a plate 10. A pressure belt 13 holds the leaves on the belt 11 and the stem butts are separated by arms 16, Fig. 6, on slowly rotating shafts 17 in a casing 14 cut away at 15 to provide a passage for the butts. The separated butts are delivered by a star wheel 30, Figs. 3 and 5, to a pocketed wheel 31 co-operating with a concave block 61 to deliver the butts between a continuouslydriven belt 62 and a pulley 63. The shafts 39, 45 of the wheels 31, 30 are geared together and are driven intermittently by a ratchet wheel 52 actuated by a pawl 51 carried by a gear 38, which is loosely mounted on the shaft 39 and is driven by a gear segment 37 actuated through a rod 34 and arm 35 from an eccentric 33 on a main drive shaft 18. In order to determine the effective stroke of the pawl 51, an arm 55 loose on the shaft 39 carries a curved plate 57 and a feeler 56 extending into the path of the stem butts. When a butt has been advanced by the wheel 31 into engagement with the belt 62 and pulley 63, the feeler 56 returns into contact with the next butt S<1> and the consequent position of the plate 57 determines the point at which the pawl 51 rides off the plate into engagement with the ratchet wheel 52. The leaf stems are delivered from the belt 62 and pulley 63 between opposed runs of conveyer chains 71, 72, Fig. 7, from which the leaves hang, and any entangled leaves are separated by rakes comprising bent pins 81 on bars 80 carried by inclined endless chains 79 running on sprockets 78 on shafts supported by a casing 75 and driven from the shaft 18 through a chain 83 and a gear-box 85. The stem butts are next delivered to an accelerating and separating device comprising a series of rollers 90, Fig. 9, driven at progressively increasing speeds by an endless sprocket chain passing around sprocket wheels of decreasing size on the shafts 94 of the rollers 90. Plates 91, 92 disposed between adjacent series of rollers 90 have undulating edges forming an indulating slot to guide the stems, to which a twirling motion is imparted by the rollers, due to the coaction of a roller with an opposed roller revolving at greater or less speed. The upper plates 91 are adjustable by means of screws 96 and the plates 92 are yieldingly supported by spring plates 101. The leaves delivered between a belt 135 and a roller 90 move control fingers 139, 145, Fig. 12, actuating switches 143, 150 controlling the circuit of a solenoid by which a clutch on a drive shaft 111 for the rollers 90 is controlled. The switches are in parallel and if a gripper wheel 207 fails to remove the foremost stem resting on the finger 145, both switches are opened and the solenoid disengages the clutch until the stem has been removed. The gripper wheel 207, Figs. 1, 14 and 16, is mounted on a sleeve 206 driven through spur and bevel gearing 200 ... 205 and chain gearing 193 from a sleeve 187b, which is loose on a shaft 188 and is driven through a pawl and ratchet 189, 190 from a crank disc 184 on a shaft 183. The latter is driven from the stemming machine through chain and bevel gearing. The wheel 207 comprises pairs of gripper jaws 219 pivoted on studs 220 and connected to a slide 214 by links 217 provided with springs 223. The slide 214 is moved diametrally of the wheel 207, to open and close the jaws 219, by the engagement of a pin 212 on a head 211 of a shaft 208 with a groove 213 in the face of the slide. At its other end, the shaft 208 has an arm 209 and pin 210 engaged by a plate 222 on a vertically movable and oscillatable rod 235, Fig. 15. Vertical movement of the rod, to bring the plate 222 into and out of the path of the pin 210, is effected by a cam 230 and levers 232, 234 mounted on a shaft 233, while oscillation of the rod, to bring one or other end of the plate 222 into the path of the pin after successive halfrevolutions thereof, is effected by a cam 242 through an arm 244, rod 245 and arm 246. The grippers 219 deliver the leaves to a gripper turret H, Fig. 1, comprising discs 250, 251, Fig. 17, on the sleeve 187b on the shaft 188. Four pairs of gripper jaws 252 are pivoted between the discs on pins 253 and connected by links 255 to blocks 256, each sliding over a guide 257 and actuated from a cam 262 by an arm 258 through a spring 263. The cam 262 is mounted on a bushing 187a loose on the sleeve 187b and oscillated by the rocker arm 187 and rod 186 from the crank disc 184 on the shaft 183. A spring-pressed latch 264 pivoted on each arm 258 engages a bar 265 and holds the gripper jaws closed during part of the rotation of the turret. A ratchet wheel on the sleeve 187b is actuated by a pawl 189 on the rocker arm 187 and at each operation the turret is advanced a quarter of a revolution to bring an open pair of jaws 252 from position IV to position I, where they are closed on a leaf stem held by the jaws 219 of the wheel 207. The jaws 252 remain closed at positions II, III and at position IV are opened to deliver the stems to the grippers of a stemming machine, the latch 264 being released by means of a cam on the shaft of the stemming machine. At the end of each advance movement, the gripper turret is locked by pawls engaging the ratchet wheel 190 until released by a trip member on the rocker arm 187. The gripper wheel 207 may be omitted, the gripper turret H being arranged in an inclined position similar to that of the wheel 207.