US3863990A

US3863990A - Pneumatic feed system having a call-dump-fill cycle

Info

Publication number: US3863990A
Application number: US298291A
Authority: US
Inventors: Jr Francis J Ballard
Original assignee: Brown and Williamson Tobacco Corp
Current assignee: Brown and Williamson Holdings Inc
Priority date: 1972-10-17
Filing date: 1972-10-17
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

A pneumatic tobacco feed system to cigarette making machines operates on a call-dump-fill and thereafter hold cycle. The system includes a discharger over each hopper of a making machine. The discharger is designed to contain a charge of tobacco while awaiting a low tobacco level call signal from the associated maker to dump this tobacco into the hopper. A pneumatically actuated air cylinder assembly operates to maintain the discharger door in a closed position until this signal is received. The cylinder rod is not permanently attached to the discharger door thereby eliminating any requirement of critical adjustment of the cylinder assembly mounting position. The extension of the rod during the door closing is at reduced speed to minimize the possibility of damage to the discharger door.

Description

United States Patent Ballard, Jr.

Feb. 4, 1975 PNEUMATIC FEED SYSTEM HAVING A CALL-DUMP-FILL CYCLE Francis J. Ballard, Jr., Louisville, Ky.

Assignee: Brown & Williamson Tobacco Corporation, Louisville. Ky.

Filed: Oct. 17, 1972 Appl. No.: 298,291

Inventor:

U.S. Cl. 302/28, 251/634 Int. Cl B60! 8/00 Field oi Search 302/28, 59, 6|; 251/54,

References Cited UNITED STATES PATENTS Primary Examiner-Stanley H. Tollberg Assistant Examiner-Hadd S. Lane Attorney, Agent, or Firm-Finnegan, Henderson, Farabow & Garrett [57] ABSTRACT A pneumatic tobacco feed system to cigarette making machines operates on a call-dump-fill and thereafter hold cycle. The system includes a discharger over each hopper of a making machine. The discharger is designed to contain a charge of tobacco while awaiting a low tobacco level call signal from the associated maker to dump this tobacco into the hopper. A pneu' matically actuated air cylinder assembly operates to maintain the discharger door in a closed position until this signal is received. The cylinder rod is not permanently attached to the discharger door thereby eliminating any requirement of critical adjustment of the cylinder assembly mounting position. The extension of the rod during the door closing is at reduced speed to minimize the possibility of damage to the discharger door.

6 Claims, 12 Drawing Figures PATENTEB H975 SHEEI 02 0f 10 PATENTEDFEH M975 sum user 1 FIG. 4

PMENTED FEB 4593 SHEET OHUF 10 FIG. 6

Z-LL

PATENTED SHEEI ES 0F 10 PATENTED FEB 5 PATENTED 3.883.990

SREEI 080F 10 PATEHTED FEB 4 PHENTED H975 SHEEI IOUF 10 PNEUMATIC FEED SYSTEM HAVING A CALL-DUMP-FILL CYCLE BACKGROUND OF THE INVENTION Pneumatic tobacco feed systems and dischargers of the type disclosed in commonly assigned U.S. Pat. Nos. 3,386,773 granted June 4, I968 and U.S. Pat. No. 3,580,644 granted May 25, l97l have proven to be eminently successful and satisfactory for conventional speed cigarette making machines. With the advent of the use and installation of relatively high speed cigarette making machines, it has become extremely desirable for optimum machine performance to maintain a more uniform tobacco level in the hopper than that capable of being attained heretofore.

SUMMARY OF THE INVENTION The present invention relates to a pneumatic feed system which is capable of maintaining relatively uniform tobacco levels in the hopper of high speed cigarette making machines.

Another object is to provide a pneumatic feed system which operates on a call-dump-fill and hold cycle which significantly reduces hopper level variations because of the full charge of tobacco over the hopper awaiting a low level call to dump.

A further object is to provide an improved discharger construction in which means are provided for holding the discharger door in a closed position during the filling and holding stages of the cycle.

Other objects and advantages will become apparent from the following detailed description which is to be taken in conjunction with the accompanying drawings illustrating a somewhat preferred embodiment of the invention.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a schematic plan view of a pneumatic feed system incorporating the teachings of the present invention and showing a plurality of dischargers, each associated with a cigarette making machine and a common feeder;

FIG. 2 is a front elevational view of the discharger of this invention shown associated with the hopper of a cigarette making machine;

FIG. 3 is a top plan view of the discharger of FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2 showing the association of the air cylinder assembly with the discharger door;

FIG. 5 is a fragmentary view of the discharger showing the door open and contained tobacco being discharged;

FIG. 6 is a diagramatic view of the signal input converter circuit for converting the input signals to logic level;

FIG. 7 is a diagramatic view ofthe input gate and flipilop circuitry for actuating the dump one-shot circuit and consequently the energization of solenoids coupled with the dump air cylinders causing the discharger doors to open;

FIG. 8 is a diagramatic view of the dump one-shot circuitry;

FIG. 9 is a diagramatic view of the memory output gate circuitry;

FIG. 10 is a diagramatic view of the reset circuitry;

LII

FIG. I I is a diagramatic view of the memory flip-flop circuitry; and

FIG. I2 is a diagramatic view of the timing circuit.

DETAILED DESCRIPTION Referring initially to FIG. 1, the pneumatic conveying system of this invention is illustrated in which a cut tobacco storage area is provided at which is located at least one feeder II]. In the illustrated system, a selected number of cigarette making machines 12a to I2d are employed for manufacturing the same brand of cigarette. A main feed pipe 14 receives the cut tobacco fed by the feeder I0 and by means of branch lines cooperates in directing the cut tobacco to the makers. As explained in detail in the above referenced patents, the operation of each feeder I0 is controlled by a pressure differential switch located adjacent the feeder discharge end and in the main feed pipe 14. When the air flow in the main feed pipe I4 reaches conveying velocity, the pressure differential switch senses this condition and causes the feeder [0 to be energized. The main suction line 16 is coupled with all of the makers 12 by branch lines as illustrated. Each of the makers 12 have associated therewith a tobacco separator or discharger 18 which operates to receive the pneumatically conveyed tobacco and when needed deposit it into the hopper of the associated maker 12. Each of the dischargers I8 is provided with a check valve 22 at its air inlet end and a suction valve 20 at its air discharge end.

The discharger 18 is mounted over the hopper 24 of the associated cigarette making machine. This machine may assume the form of any one of a number of commefically available cigarette making machines but as indicated in the foregoing, it is contemplated that the pneumatic tobacco feed system of the present invention would be peculiarly adapted for association with high speed cigarette making machines. Currently, machines of this type are capable of producing as much as 4,000 cigarettes per minute and more. Hopper 24 may include Sonac relay sensors (not shown) or other suitable means for responding to the level of tobacco in the hopper to register the call for tobacco held in the associated discharger 18. When this occurs the contained tobacco will be deposited into the hopper. Thereafter, cut tobacco will enter the discharger l8 through the check valve 22 and till the compartment 26 immediately below the separating screen 28 with the air stream passing on through the open suction valve 20. The separator screen 28 may be sloped upwardly in a manner taught by U.S. Pat. No. 3,580,644. When the compartment 26 is nearly full, screen 28 is very nearly blocked thereby causing a relatively high differential pressure across the screen. A differential pressure switch 30 (DPS) communicating with both the upstream and downstream side of the separator and across the screen 28 is actuated to cause the suction valve 20 to close. Subsequently, the trap or discharge door 32 will open and release the accumulated tobacco into the cigarette making machine hopper 24. The valve 22 is disc shaped and is hinged and when in a closed position it will be sucked tightly into the inlet end of the of the adjacent feed pipe. The suction valve 20 is shifted from a fully opened to a fully closed position by means of the piston-cylinder assembly 34.

An air cylinder assembly 36 operates to hold the discharger door 32 in a substantially closed position while tobacco fills the compartment 26 and until the associated cigarette making machine demands tobacco. The assembly 36 is mounted on a bracket 38. The free end of the rod of the piston is provided with a knob or ball 40 which is adapted to engage the door 32 and shift it to a closed position. In this connection, the stroke of the cylinder is adjustable and preferably holds the door a slight amount from its fully closed position. in this manner, it is not necessary to attach the cylinder rod to the door and thereby render the cylinder position critical. in addition. damage to the door is prevented as the result of possible cylinder over-travel. The assembly 36 may operate off air and is provided with a flow control valve 42 which may be adjusted for relatively slow cylinder rod extension to further minimize damage to the door 32 when the ball 40 makes contact with the door and as it is being gently pushed to its almost closed position. When a call for tobacco is received, the assembly 36 is actuated to retract the cylinder rod and consequently the ball 40 thereby permitting the door 32 to swing open. The cylinder of the assembly 36 may be equipped with a cushion at its inner rear end to prevent shock in the cylinder as the rod is retracted at full speed.

The control circuitry illustrated in FIGS. 6 to 12 is designed to handle four cigarette making machines operating on a call-dump-fill and hold cycle with a first in. first out memory. Open receipt ofa call from the sensor in hopper 24 of a making machine 12, the following sequence of events will occur. Initially, the call will be stored in the memory, the dump solenoid associated with the air cylinder assembly 36 will be de-energized, permitting the ball 40 to retract for a predetermined period of time. During this interval, the tobacco from the discharger 18 is dropped by gravity into the hopper 24 of the machine 12. When this period of time has elapsed which should be sufficient to discharge all of the tobacco within the discharger 18, the dump solenoid is energized causing the air cylinder 36 to extend, thereby closing the door 32. At the same time, the suction valve 20 is opened (if another discharger is filling at this time, the unit must await its turn) placing the particular discharger in its full cycle. The suction, in turn, causes the discharger door to be drawn completely closed as well as the check valves 22 in the other three dischargers to close and when the pressure is sufficiently negative at the feeder 10 to indicate the presence of conveying velocity, the feeder is started and tobacco is fed into the system. When the suction valve 20 is opened, a timing unit is started. The discharger is now filling with tobacco. When the discharger is filled, as sensed by the differential pressure switch 30 or the timing unit times out, the memory is reset causing the suction valve 20 to close to end the cycle. The discharger 18 is now filled with tobacco and the door is held shut by the ball 40. Upon receipt of the next call by this maker, the cycle will be repeated. Thus, a more uniform level of tobacco in the making machine is obtained as well as reducing the amount of time a discharger has to wait to be refilled. It should be noted that upon receipt of a call, the discharger 18 dumps its tobacco immediately and then, if there must be a wait for the fill cycle, it occurs only after the dump cycle has been completed.

In the illustrated circuitry of FIGS. 6 to 12 and in accordance with a successful embodiment of the invention, the logic utilized is positive logic with being zero volts and l being volts. The input signals and the signals of the Sonacs and pressure differential pressure switches 30 are US volt AC signals. The input converters 44 convert this l l5 volt AC input signal to a logic level of zero volts and +5 volts. For purposes of the description below the circuitry, it is assumed that the discharger 18 has been filled with tobacco and is now awaiting a call. When an input is received indicating a low hopper at the indicated first discharger (number l the signal at I-LL becomes a l .1 asmuch as flip-flop 48a is not set at this time, signal 111 is also a l." These signals are anded through the noninverting set input gate 46 causing the gate 46 to be come a l which sets flip-flop 48a and signal T becomes a l and signal lTi becomes a 0." Logic elements 49a to 49d are utilized in the input flip-flop register as inverters. This is necessary as on this particular logic card only the set output is available. Therefore, the reset output is obtained by inversion. When Ill goes to 0," it makes the set input gate 460 go to 0" removing the set signal from flip-flop 48a and also fires one-shot 50. One shot 50 goes from l to 0" for approximately 8 seconds which is generally sufficient time within which to permit the tobacco to be discharged from the discharger 18 when the door 32 has opened. Logic elements 51a and 51!) are one-shots which are used to control the dump cycle. They fire for approximately 8 seconds. A unit cannot proceed into the fill cycle until these one-shots time out, thereby assuring that sufficient time has elapsed for previous charge to have been dropped into the making machine hopper. During this interval, the dump solenoid is deenergized causing retraction of the ball 40 and permitting the discharger door 32 to open. Logic element 53 is an isolated A.C. switch used to convert the +5 volt D.C. logic level signals to 1 l5 volt AC outputs. Meanwhile, when flipflop 48 was set, signal lll becomes a l and went into the memory circuitry (the complete function of this circuit will be fu l l discussed later). This caused signals at T17, Ti? and 114 to become a l 's," and since signal H6 is also a l, the and-expanded non-inverting gate 52 causes the signal at "8 to be come a 1" after a 10 micro-second delay. Since the logic transitions on 111 and T discussed above start at the same time, th e delay permits one-shot 50 to fire bringing signal at 120 to "0" prior to rise of 1 l8 to l to prevent a false spike from entering the timing circuits.

When one-shot 120 times out," signal 120 becomes a l and since it is anded through a non-inverting gate 54 with the signal "8, signal 121 becomes a l energizing the output to the solenoid of the suction valve 20. The suction valve 20 opens, permitting the system to start the fill cycle. Logic element 55 is an isolated A.C. switch used to convert the +5 volt D.C. logic level signals to volt A.C. outputs.

At the same time, the signal at 12] starts the timing circuit (to be discussed later) which contains the only adjustable timer in the circuitry of the illustrated embodiment. This timer is adjustable to a maximum of approximately 21 seconds and should normally be set in the range of 15 to 18 seconds.

The signal at 121 also partially enables the and/or expanded inverting gate 56 of the reset circuits. When the discharger 18 has been filled and the differential pressure switch 30 has been actuated, signal l-DPS is anded with the signal at 121 and gate 56 becomes a 0" or if the differential pressure switch 30 does not actuate before the timing circuit times out. the output I22 of the timing circuit becomes l and is anded with that of I2I, causing gate 56 to go to 0. This timer limits the duration of the call if the differential pressure switch 30 is not working properly. When gate 56 goes to 0" it fires one-shot 58 causing I24 to become a I for approximately one-half second. The signal at I24 resets flip-flop 48 and holds it in the reset state for the duration of the one-shot. (It should be remembered that the reset input to flip-flop 48 takes precedence ovef the set signal so that the flip-flop will remain in the reset state regardless of the condition of the set input for the duration of the reset signal.) When flip-flop 48 is reset, its output at III becomes a zero and at TIT goes to a When III becomes a memory gate 52 changes state and I18 becomes a 0" causing gate 54s output 121 to become a 0" de-energizing the solenoid of the suction valve 20, thereby terminating the fill cycle. When location I2I goes to "0 the timing circuit is reset to disable the reset circuit. However, since the reset one-shot 58 is looped on itself, the reset signal 124 remains a l for one-half second before going to When signal III went to a Of the memory was permitted to select the next maker, calling for more tobacco.

When location TIT became a I one-shot 50 was reset and set input gate 46s input at Tfi was enabled permitting flip-flop 48 to be set again on the disappearance of reset signal at 124 if and when signal l-LL is a I When the signal at I2I becomes a 0, l-shot 60s output I16 went to a 0" for approximately one-half second, this signal at II6 disables all memory output gates for one-half second to gain the desired sequencing of suction valves should another unit discharger I8 have completed its dump cycle and is awaiting its turn to fill.

The foregoing description takes a single call through the complete cycle and leaves the unit discharger ready to receive the next call. If any other maker had called at any time during the above sequence of events, it would have set its respective flip-flop 48, gained a place in line in the memory system based on the order in which the calls were received, proceeded through the dump portion of the cycle and then waits for its turn to fill.

Turning now to the memory circuit, it will be noted that it is composed of six R-S flip-flops 62a to 62], each made up of two cross-coupled inverting gates and their associated memory output gates. The truth table for a R-S flip-flop is shown below:

Input I I l Input 2|] Output 2T5 Output TIE 0 l l 0 l U 0 l l I No change from last state 0 U l I that the inputs to it will call in the following order: 41 I, 211,111, and 3H. With no unit dischargers calling, all inputs (111, 2", 3", 4| I) to the flip-flops 62 will be 0s." Therefore, all outputs will be 1 based on the ambiguous state of the flip-flops. The inputs to the output gates will all be l 5" except for inputs 1] I, 2! I, 311 and 411.

When input 4]] becomes a l," outputs IN, E and 3? go to 0" disabling all memory output gates, except that coupled with 411. Gate 52d thus goes to a I and energizes an output. Next input 21] becomes a I. Accordingly, outputs I12 and m become 0's. Output 721 remains a l since these flip-flops set and reset on Os," and a change from 0" to I of an input will not change the state ofa flip-flop. The state of output memory gates is now aJfollows:

Gate 52a Output Iltla U Gate 52!) Output 18h U Gate 52: Input 3| 1 In ut 3 Ingut {5 Input 341 I 16 Input w Input 4I2 Input 1? Input 46'] Output 1 I 0 Gate 52d Output 1 I811 l Now, input Ill becomes a and output 312 goes to a 0." None of the other flip-flops change state on this 0" to I transition. The state of the output memory gates is as follows:

Gate 520 Input I I I Input Ill 0 Input I Input Output l I80 0 Input Gate 52c Input 3II Output ll8c 0 Input 0 Input I Input 33'] I I6 4 I Input Il 2 Input m Input 4'31 I 16 O I Gate 52! Input I Output I I811 l l I I I Now, input 3Il becomes a 1" but no outputs change state. The memory is now loaded for all four dischargers 18 in the order in which they called: 411, 211, Ill, 31]. By looking at the state of the memory output gates 52, it can be seen that they will come out in the same order they were put in.

However, for purposes of illustration, we will now cancel input 41] (as if it had completed its dump-callfiil cycle) causing it to go to 0. When output 4]] goes to 0," then tp t M LE, and W become I s" and outputs 412, 42] and 431 become 0s." The state of memory output gates is shown below:

Input ii I Input ll Output 1 l8h l Gate 52(- Output lltir' Gate 52:! Output ill id As was expected, the second discharger 18b came in line when the fourth discharger cancelled. Once again, an inspection of the gate conditions shown above shows that when the signal at 211 cancels, discharger no. 1 (18a) will be activated, and when discharger no. 1 cancels, discharger 2 (18c) will come on. By following the action ofthe flip-flops, it will be further seen as the various units continue to cancel, the flip-flops proceed to return to their ambiguous state in proper sequence.

Referring now to the timing circuit, it will be appreciated that this circuit is activated by any of the signals at 12] which go to a l since these signals are ored" together. Once again, we will select the signal at 1210 as an illustration. Thus, when the signal at 1210 goes to l," the inverting or gate output 64 goes to O," which causes timer 66 to start timing and inverting gate 68 to go to l which resets one-shot 60. When discharge no. 1 (18a) is cancelled by signal l-DPS or signal 122 becoming a l," the reset circuit is actuated and propogates to the main line logic causing [21a to go to When 121a goes to gate 645 output becomes a l causing timer 66 to reset and gate 68 goes to which fires one-shot 60. Signal 116 goes to 0 for approximately one-half second disabling the memory output gates, thereby preventing any suction output from being actuated, and permits timer 66 to be reset long enough to recover to at least 95% repeat accuracy of timing. This circuit is now ready for another cycle.

Thus, the several aforenoted objects and advantages are most effectively attained. Although, a single somewhat preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

I claim:

1. A tobacco discharger for association with a cigarette making machine and an automatic tobacco conveying system which pneumatically conveys tobacco from a storage area to the discharger and ultimately to the associated cigarette making machine with the sys' tem including a main feed pipe for coupling with the source of the stored tobacco and the tobacco discharger, air differential pressure means for forcing air through the pipe at a predetermined conveying velocity, a tobacco feeder at the source of stored tobacco for feeding the tobacco into the main feed pipe, the tobacco discharger comprising:

a housing having an air inlet and means for coupling the air inlet with the main feed pipe, an air discharger and a tobacco discharge opening defined by an abutment closure surface,

tobacco separating means within the housing for separating tobacco carried by air entering the air inlet end, the tobacco separating means including a tobacco separating screen arranged within the housing intermediate the inlet and discharge,

valve means for stopping the flow of the air through the discharger,

door means forming part of the discharger housing and adapted to be shifted from a closed position during filling of the housing with tobacco and until such time as the separated tobacco is to be discharged into the associated cigarette making machine to an open position where the tobacco within the housing is discharged under the influence of gravity into the associated cigarette making machine, said door means being hingedly connected to said housing at said tobacco discharge opening and swingable through an arc downwardly to discharge the tobacco and upwardly into sealing engagement with said abutment closure surface on the housing, said abutment closure surface being in the path of said are so that the door will seal the discharge opening, and

discharger door actuating means engaging said door means for moving the door means to a position slightly spaced from the abutment closure surface and holding said door means in said position after filling of the housing with tobacco and until such time as the cigarette machine signals a demand for tobacco, said actuating means then permitting the door means to open whereby the tobacco is discharged into the associated cigarette making ma chine, the actuating means being comprised of a cylinder assembly having a piston rod with a free end, means at the free end for sliding engagement with the surface of the door means for shifting the door means from an open position through a portion of said are towards a closed position, the stroke of the piston rod being such that the door means is moved through only a portion of its arc to a position in spaced relation to said abutment closure surface whereby, upon application of pneumatic pressure in the system, said pressure causes the door means to swing through the remainder of said arc and upon deactivation of the pressure, the door means drops to the slightly spaced position and is retained at that position by the piston rod until tobacco is required by the cigarette making machine and then the piston rod is retracted to allow the door to open, said movement to a spaced position avoids damage to the door by the piston rod in that the rod does not drive the door into sealing relation and further avoids the necessity for critical adjustment of the operating stroke of the piston rod.

2. The invention in accordance with claim I wherein the piston rod and consequently the ball is adapted to be retracted away from the door at a relatively fast speed when it is desired to discharge the tobacco in the housing into the associated cigarette making machine and a lower speed when the piston rod and the associated ball is shifted into engagement with the door and when shifting the door from an open position to a substantially closed position.

3. The invention in accordance with claim 1 comprising the combination of automatic tobacco conveying system. a plurality of said tobacco dischargers and a like number of cigarette making machines, each of which is associated with a discharger, with control means for operating each discharger on a call-dump-fill and hold cycle, wherein tobacco will be contained in the housing ready for discharge when it is desired to discharge this tobacco into the cigarette making machine.

4. The invention in accordance with claim 3 wherein circuitry forms part of the control means to allow tobacco to be discharged immediately upon receipt of a call.

Claims

1. A tobacco discharger for association with a cigarette making machine and an automatic tobacco conveying system which pneumatically conveys tobacco from a storage area to the discharger and ultimately to the associated cigarette making machine with the system including a main feed pipe for coupling with the source of the stored tobacco and the tobacco discharger, air differential pressure means for forcing air through the pipe at a predetermined conveying velocity, a tobacco feeder at the source of stored tobacco for feeding the tobacco into the main feed pipe, the tobacco discharger comprising: a housing having an air inlet and means for coupling the air inlet with the main feed pipe, an air discharger and a tobacco discharge opening defined by an abutment closure surface, tobacco separating means within the housing for separating tobacco carried by air entering the air inlet end, the tobacco separating means including a tobacco separating screen arranged within the housing intermediate the inlet and discharge, valve means for stopping the flow of the air through the discharger, door means forming part of the discharger housing and adapted to be shifted from a closed position during filling of the housing with tobacco and until such time as the separated tobacco is to be discharged into the associated cigarette making machine to an open position where the tobacco within the housing is discharged under the influence of gravity into the associated cigarette making machine, said door means being hingedly connected to said housing at said tobacco discharge opening and swingable through an arc downwardly to discharge the tobacco and upwardly into sealing engagement with said abutment closure surface on the housing, said abutment closure surface being in the path of said arc so that the door will seal the discharge opening, and discharger door actuating means engaging said door means for moving the door means to a position slightly spaced from the abutment closure surface and holding said door means in said position after filling of the housing with tobacco and until such time as the cigarette machine signals a demand for tobacco, said actuating means then permitting the door means to open whereby the tobacco is discharged into the associated cigarette making machine, the actuating means being comprised of a cylinder assembly having a piston rod with a free end, means at the free end for sliding engagement with the surface of the door means for shifting the door means from an open position through a portion of said arc towards a closed position, the stroke of the piston rod being such that the door means is moved through only a portion of its arc to a position in spaced relation to said abutment closure surface whereby, upon application of pneumatic pressure in the system, said pressure causes the door means to swing through the remainder of said arc and upon deactivation of the pressure, the door means drops to the slightly spaced position and is retained at that position by the piston rod until tobacco is required by the cigarette making machine and then the piston rod is retracted to allow the door to open, said movement to a spaced position avoids damage to the door by the piston rod in that the rod does not drive the door into sealing relation and further avoids the necessity for critical adjustment of the operating Stroke of the piston rod.

2. The invention in accordance with claim 1 wherein the piston rod and consequently the ball is adapted to be retracted away from the door at a relatively fast speed when it is desired to discharge the tobacco in the housing into the associated cigarette making machine and a lower speed when the piston rod and the associated ball is shifted into engagement with the door and when shifting the door from an open position to a substantially closed position.

3. The invention in accordance with claim 1 comprising the combination of automatic tobacco conveying system, a plurality of said tobacco dischargers and a like number of cigarette making machines, each of which is associated with a discharger, with control means for operating each discharger on a call-dump-fill and hold cycle, wherein tobacco will be contained in the housing ready for discharge when it is desired to discharge this tobacco into the cigarette making machine.

5. The invention in accordance with claim 4 wherein timing circuitry forms part of the control means for deactivating the actuating means to permit the hopper door to open for a predetermined period of time in order to permit the tobacco in the discharger to be discharged.

6. The invention in accordance with claim 5 wherein memory circuitry is included so that after a discharger has discharged its previous charge, its filling is delayed if another discharger is filling at this time, and each discharger will be filled in the order that its call is received.