Patent GB-475870-A (GB)
Title: Improvements relating to apparatus for pneumatically conveying tobacco to tobacco working machines
IPC: A24C5/39
Filed: 1936-05-22
Abstract: 475,870. Feeding tobacco to cigarette-making &c. machines. AMERICAN MACHINE & FOUNDRY CO. May 22, 1936, No. 14495. Convention date, Feb. 25. [Class 130] [Also in Group XXX] An apparatus for conveying tobacco to a number of receiving chambers, which may be associated with cigarette-making, tobaccopackaging or other machines, comprises a conduit through which tobacco is conveyed by an air current, and a mechanism associated with each chamber operable to close the conduit and to divert the air current along a branch path including a portion of the chamber in order to cause the separation and deposit of the tobacco within the chamber. As shown in Fig. 1, a conduit is connected to a suction fan F and associated with delivery devices H<1> . . . H<3> each connected to the feed hopper of one of the cigarette-making machines M<1> . . . M<3>. Tobacco is supplied to the conduit 21 by an intake mechanism G from a feed table 20, which may be placed in a tobacco storage room to which conditioned air taken from the room through the conduit 21 is returned through the discharge pipe 23 of the fan. The intake mechanism, Figs. 1 and 2, comprises a casing 32 connected alternatively by a pedal-actuated slide valve 29 to an inlet pipe 39, into which tobacco is fed by the operator, or to a pipe 37 leading from a dust-collecting chamber 35 under a screened part of the feed table 20. The valve 29 is normally locked by a pin 53 on the core of a solenoid 51, and controls a four-pole switch 57, the stem of which has a roller engaging an inclined cam surface on the valve 29. Each of the delivery devices H<1> . . . H<3> comprises a shoot 92, Figs. 7 and 12, having at its lower end a pair of trap doors 93 opened by gravity and closed by compressed air admitted through a pipe 104 to a cylinder 103 containing a piston 100 connected by links 97 to arms on the doors 93. A delivery valve 77 slides in a casing 76 interposed in the conduit 21 and has a curved delivery passage 89, which in the position shown in Figs. 12 and 13 diverts tobacco from the conduit 21 into an inlet pipe 91 leading to the shoot 92, in which is a curved baffle plate 106. The air stream escapes from the shoot through a screen 105, elbow 108, and a second passage 88 in the valve 77, and is returned through a passage 110 in the casing 76 to the succeeding section of the conduit 21. In the normal (open) position of the valve 77, the passage 88 is in line with the conduit 21 and no tobacco is delivered to the shoot 92. The valve 77 is actuated by a piston 78 moving in a cylinder 80 connected at each end by pipes 83, 84 to the cylinder 61 of a piston valve 64, Fig. 11, adapted to connect one or other of the pipes 83, 84 to a compressed-air pipe 63 and the other to an exhaust port 72. The valve 64 is moved in one or other direction by solenoids O<1>, K<1>. Arms 113, 114 on the ends of the delivery valve 77 are adapted to close one or other of switches N<1>, Z<1>. Each cigarette-making machine M<1> . . . M<3> is fitted with an automatic control switch I<1> ... I<3> for periodically opening a circuit including a corresponding signal lamp S<1> ... S<3> for notifying the operator that the machine needs replenishing. The switch I' comprises a control arm 210, Fig. 11a, actuated by a cam 209 driven intermittently through a one-way clutch 206 from a rocker arm 204 oscillated by the rod 202 of an eccentric 201 on a chaindriven shaft 200. A spring-pressed eccentric stop 208 prevents backward movement of the clutch member 206, and the rod 202 is connected to the arm 204 by means of a block 203 adjustable in a slot in the arm. The control circuits, Fig. 14, include a switch LS for connecting the system to supply lines L', L<2>, and relay switches PR<1> &c. actuated by the closure of the corresponding switches I<1>. . . I<3>. Each switch PR<1> &c. closes the circuit of one of the signal lamps S<1> . . . S<3> and also closes a circuit including a pushbutton B<1> . . . B<3> and a solenoid O<1>. . . O<3> actuating the piston valve 64, and a circuit including in series the normally closed switches Z' ... Z<3>. The operator presses the button B<1> corresponding to the signal lamp S<1>, and the solenoid O<1> by means of the valve 64 sets the valve 77 to deliver tobacco into the shoot of the corresponding machine. The movement of the valve 77 opens the switch Z' and closes the switch N<1> in a circuit including a secondary relay SR<1>; this breaks the circuit including the relay PR<1>, which opens the circuits of the push-button and the signal lamp. The relay SR<1> also closes the circuit of the latch solenoid 51, allowing the operator to open the valve 29 and supply tobacco to the intake 30 of the conduit 21. The movement of the valve 29 effects the closure by the switch 57 of a circuit including a time relay TR carrying a bar L controlling contacts M, N, P. The bar opens the contact M to de-energize the latching solenoid 51 and to allow the valve 29 to be relatched when returned by depression of the pedal 48, whereupon the switch breaks the circuit of the time relay. The latter is set so that the bar L closes the contact N, while allowing the contact P to remain closed, after an interval allowing time for the tobacco to travel to the farthest delivery device H<3>, so that a circuit including the solenoids K<1> ... K<3> is momentarily energized and the solenoid K<1> corresponding to the solenoid O<1> previously operated will return the valve 64 to the position shown in Fig. 11 ; this effects the return of the delivery valve 77 and allows the opening of the trap doors 93 to discharge the tobacco into the feed hopper of the machine M<1>. The return of the valve 77 also causes the switch N<1> to open the circuit of the relay SR<1> and thus to complete the circuit of switches I<1> and PR<1>; the switch Z<1> is also closed by the contact arm 114, so that the mechanism is restored to its original condition. If the tobacco level in the feed hopper of any machine runs low before the switch I<1> &c. is operated, a signal may be sent by means of a hand-actuated switch 116 in parallel with I<1> ; and a knife switch 117 on each machine interrupts the circuit of the controlling switch when the tobacco level is too high. In a modification, the intake valve 29 is actuated by a piston actuated by compressed air under the control of a piston valve similar to 64, Fig. 11, and moved by solenoids in series with the solenoids O<1> ... O<3> and N<1> ... N<3>, the latch 53 and solenoid 51 being omitted. Specification 475,926 is referred to.