US3548841A - Cigarette smoking machines - Google Patents

Description

United States Patent [72] lnventor [21'] App1.No. [22] Filed [45] Patented [73] Assignee [54] CIGARETTE SMOKING MACHINES 15 Claims, 7 Drawing Figs.

[52] U.S.Cl. 131/171, l3l/175.13l/182.131/185.131/l87;73/28 [51] lnt.(l ..A24t'13/10, A24f47/00; A24d H12 [50] FieldofSearch 131/170, 171,172,195,187,l85,l79;73/23,28;130/171 [56] References Cited UNITED STATES PATENTS 3,433,054 3/1969 Mutter 73/28 214,586 4/1879 Riedel 131/179X 796,002 8/1905 McKay..... 131/187 1,692,971 11/1928 Alland 131/179 1,740,334 12/1929 Churchill.. 131/172 1,864,400 6/1932 Berger 131/171X 2,228,216 1/1941 Morgan 73/28X 2,366,686 l/1945 Halloran 131/187X 2,563,695 8/1951 Siens 131/175 2,776,662 l/1957 Widrich 131/179X FOREIGN PATENTS 1,290,569 3/1962 France 131/179 450,631 10/1927 Germany 131/172 OTHER REFERENCES Pge. 45 of Dont Let Smoking Kill You," a booklet by Clarence W. Lieb, M.D. Published 1957 by Bonus Books, Inc., of 122 E. 42nd Street, New York, N.Y. A copy of Page 45 may befound in 131 171,the Booklet, in 131- 1.

Primary Examiner-Joseph S. Reich Attorney-Holcombe, Wetherill and Brisebois ABSTRACT: An automatic cigarette smoking machine having a smoking head which rotates about a vertical axis and has a ring of outwardly extending cigarette holders each formed at the end of a corresponding smoke duct. As the head continuously rotates in use the other ends of the smoke ducts move in turn into register with a stationary vacuum port through which vacuum is applied to draw smoke through cigarettes mounted in the holders in turn. The machine also includes a pneumatic system for ejecting spent butts, and extinguisher therefor and another pneumatic system including a portion of that employed by the ejector, for reloading the holders.

PATENTEU IJEL22 IQYB SHEET 1 OF 5 @TENTED DED22 I970 SHEET 2 OF 5 PATENTEUDEc2219m 3.548.841

SHEET u 0F 5 VACUUM 7 PUMP 1 FLOW 50 NEEDLE 5? CONTROLLER AVALVE NEEDLE VALVE CAM FOLLOWER SHEET 5 [IF 5 PATENTED 05022 I970 CIGARETTE SMOKING MACHINES This invention relates to machines which smoke cigarettes automatically for use in testing the burning rate and qualities of cigarettes and to produce smoke under conditions which are as natural as possible foranalysis and animal inhalation experiments.

One type of prior machine consists of a number of tubular cigarette holders carried from a common manifold to which a vacuum can be applied so that in use air is drawn continuously or at intervals through the cigarettes mounted in the holders and into the manifold. This is a convenient way of producing a large quantity of smoke quickly, but the machine is not sufficiently accurate for analytical purposes because the cigarettes are not all smoke in exactly the same controlled manner. For example the pressure drop through the different cigarettes when a puff is taken may well depend upon the relative positions of the different holders carried by the manifold.

When the smoke yield of cigarettes is to be analysed, it is necessary to be able to control the air flow through a cigarette as each puff is taken, the length of time of each puff, and the number of puffs per minute. For example, a test which is generally accepted throughout the industry in Britain consists of a pufi' volume of 25 ml., and a puff time of 2 seconds at a rate of one puff per minute, the cigarettes being smoked down to a predetermined butt length. A known machine which will smoke cigarettes under these accurately defined conditions consists of a number of static cigarette holders each coupled through a separate electromagnetically operated valve to a source of vacuum, the vacuum pressure and the opening and closing of the valves being controllable. Since a separate valve is required for each holder, the machine tends to bulky and complex if enough holders are to be provided to smoke a large number of cigarettes, for large scale tests or for producing bulk quantities of smoke condensate for analysis.

In order to try to overcome the difiiculty of smoking a large number of cigarettes simultaneously and under analytical conditions, a machine has previously been developed consisting of a rotary smoking head which is rotated in a stepwise manner about a horizontal axis against a vacuum port through which vacuum is applied. A number of cigarette holders extend axially from the head in a common plane and as the head rotates the holders move successively into communication with the vacuum port so that puffs are successively taken through cigarettes mounted in the holders. Between puffs the cigarettes remain smouldering. This machine, although overcoming some of the previous disadvantages, is unsatisfactory in that as the head indexes through each step to bring the next holder into register with thevacuum port, after each puff the cigarettes are subjected to rotational movement about'the axis of the machine. This influences the burning rate, and also disturbs the natural smouldering of the other cigarettes. The smoke rising by convection from the cigarettes in the holders at any time at the bottom of the smoking head, rises past the smouldering cigarettes at a higher level and consequently the cigarettes at the higher level burn in an atmosphere which is unnaturally hot and smokey and furthermore the cigarettes are not smoked in an atmosphere of pure air but rather in a warm atmosphere contaminated with side stream smoke of different composition to normal smoke.

The objects of the invention are to produce a cigarette smoking machine without the above mentioned disadvantages and in accordance with this invention a cigarette smoking machine comprises a smoking head which is provided with a ring of cigarette holders for supporting cigarettes so that they extend substantially radially outwards from the head and which is continuously rotated about a vertical axis to bring a series of smoke ducts inthe head, one in communication with the interior of each holder, into register with a vacuum port to which vacuum can be applied .to drawa puff through a cigarette mounted in the holders in turn.

Further objects, features, and advantages of the invention will be apparent from theaccompanying drawings which illustrate an example of a machine constructed in accordance with the invention and in which:

FIG. 1 is a plan view of the present invention with some parts omitted;

FIG. 2 is a detailed elevation as seen along the arrow II in FIG. 1;

FIG. 3 is a sectional view, with some parts omitted, and taken on the line III-Ill in FIG. 1;

FIG. 4 is a detailed elevational view as seen along the arrow IV in FIG. 1;

FIG. 5 is a schematic elevational view as seen along the arrow V in FIG. 1;

FIG. 6 is a diagram of the vacuum circuit of the machine;

FIG. 7 is a diagram of an electronic control circuit which controls the automatic recharging of the machine with cigarettes.

The machine illustrated comprises a cylindrical chamber 16 which is mounted on legs 17 and has a close fitting cover which forms the smoking head 18. The head 18 supports twenty five equiangularly spaced cigarette holders 19 by means of individual tubular necks 20 which are curbed so that the holders 19 overlie an annular ashtray 21. Each of the holders 19 includes a pair of annular flexible rubber discs 22 which are separated by spacers 23, thediscs and spacers being retained within the holder 19 by a chamfered throat piece 24 which is screwed into the holder. A cigarette 25 may be pushed through the throat piece 24 into the holder past the discs 22. The cigarette will then seal against the internal peripheral edges of the discs 22. The discs 22 may be replaced by discs having a different internal diameter to accommodate cigarettes of a different external diameter. The tubular necks 20 open at their lower ends into-circular smoke ducts 26 which extend down through the head 18 and open at the bottom surface of the head into a ring of smoke ports formed in a fiat polished lower surface of an annular depending portion 27 on the underside of the head 18. The head 18 is continuously rotated in an anticlockwise direction as seen from above over the top of the wall of the chamber 16 at a rate of one revolution per minute by means of an electric motor 28 (FIG. 5) through a worm and wheel 25:1 reduction gear 29 and a shaft 30 (FIG. 3) which extends up through bearings 31 in the bottom wall of the chamber 16 and in a fixed turret 32 and is rigidly fixed to a disc 32a to which the head 18 is screwed. The shaft 30 forms the output member of a coupling through which the shaft is driven from the worm wheel of the reduction gear 29. The input member of this coupling is formed by a cup shaped part 33 which is rigidly fixed concentrically to the worm wheel and carries a spring loaded roller 34 which is urged into an axially extending keyway 35 in the shaft 30 to engage the coupling.

The spring which urges the roller 34 into the keyway 35 is sufficiently strong to maintain the coupling engaged during normal rotation of the head 18. However, the roller 34 will ride out of the keyway 35 causing disengagement of the coupling in the event of the head 18 meeting an obstruction or being held or rotated by hand at a speed different from that at which it is driven. When the coupling is disengaged the machine is automatically rendered inoperative by means of a switch 36 which is mounted on a dish 37 rigidly fixed to the cup shaped part 33. The switch 36 is controlled by means of a magnet 38 which is carried on an arm 39 projecting outwards from a collar 40 which is rigidly clamped around and rotates with the shaft 30. When and only when the coupling is engaged, the magnet 38 overlies and closes the switch 36 and the resulting current is transmitted to the stationary part of the machine through spring loaded brushes 41 which rub over car bon rings 42 extending around the base of the dish 37. Interruption of this current, due to disconnection of the coupling, stops the motor 28.

As the head 18 rotates the annular depending portion 27 sweeps over and seals against two stationary slide surfaces. The first slide surface is formed .by a pad 43 of polytetrafluoroethylene stuck on the top of a flanged tube 44 which extends down through the bottom wall of the chamber 16 and is supported so that the pad 43 is urged resiliently upwards into engagement with the depending portion 27 by a stainless steel bellows 45. The tube 44 is sheathed in a sleeve the lower end of which is formed as a chamfered spigot 46 which is coupled by a flexible pipe 47 to a separate control unit (not shown) containing a vacuum system and other controls for the machine.

An aperture forming a vacuum port 48 is formed through the centre of the pad 43 in register with the interior of the tube 44 and with the ring of smoke ports 26. The single vacuum port 48 is elongated in the circumferential direction of the ring of smoke ports as shown in FIG. 1. As the head 18 rotates, the smoke ports in turn come into register with the vacuum port 48 and for a period in which the whole of a smoke port is in communication with the vacuum port, a shutoff valve 55 (FIGS. 3-6) in the pipe 47 opens and applies a vacuum to the corresponding holder 19 to draw air and smoke through a cigarette in the holder and down through the pipe 47. The shutoff valve in the pipe 47 is opened and closed under the control of a pair of snap action cams 49 (FIG. which are mounted on the same shaft as the worm of the reduction gear 29 and therefore rotate at twenty five times the speed of the head 18; that is one revolution per smoking cycle as there are holders 19. The cams are followed by followers 50 which operate electrical switches 50A (FIG. 6) and hence control the shutoff valve which is solenoid operated. The angular positions of the cams 49 relatively to one another can be adjusted and in this way the puff time may be readily set, within limits, to any predetermined value. In this machine vacuum is applied to each holder in turn for a period of 2 seconds so that a 2- second puff is taken from each cigarette each minute. For the rest of the 58 seconds the cigarette smoulders whilst the corresponding smoke port is in communication with the interior of the chamber 16 and hence with the atmosphere through a combined drain and vent 50a in the floor of the chamber 16. The switch 36 is connected in series with the cam controlled switches so that when the coupling through which the shaft is driven is not engaged and the switch 36 is open the shut off valve in the pipe 47 cannot be opened thus preventing a rapid succession of puffs being taken from a cigarette situated in the smoking position.

The pneumatic system of the control unit is shown in FIG. 6. The circuit includes an electrically driven vacuum pump 51 connected through a needle valve 60 to a differential flowcontroller 52 which compensates for changes in gas flow to variations in the draw resistance of the cigarettes, the actual flow rate being controlled by means of a needle valve 59.

The valve 60 is used to adjust the system to the predetermined vacuum. The flow controller 52 is in turn connected through flowmeter 53 to a solenoid operated relief and smoking valves 54 and 55, the valve 55 being previously referred to as the shutoff valve in the pipe 47. The flowmeter 55, by giving a visual display of the gas flow, assists in the initial adjustment of the required puff volume. A safety filter 56 is provided in the line 47 upstream of the valve 55. The low pressure in the circuit is measured by a gauge 57 and the reading can be maintained substantially constant by the needle valve 59 since one of the valves 54 and 55 is always open when the other is closed. Thus during a two seconds puff the valve 55 is open and the valve 54 is closed and between puffs the valve 54 is open and the valve 55 is closed. A further pressure-responsive needle valve 58 is upstream of valve 54 balances any restriction in the air flow which may be caused by any particular smoke collection unit and thereby a continuously steady reading is maintained on the flowmeter 53. The puff time and flow rate determine the actual puff volume.

The machine has provision during continuous operation for automatic ejection of a smoked cigarette butt from its holder 19 and for the recharging of the holder with a new cigarette. Initially the holders are charged by hand but thereafter when a cigarette has burned down to a predetermined butt length, this fact is sensed by a thermocouple 61 (FIGS. 1, 2 and 7) which responds to the heat radiated from the flowing tip of a passing cigarette only when the glowing tip is immediately adjacent to the element 61. When it responds the element 61 sends a signal along a line 62 (FIG. 2) to the control unit thus cocking an ejection mechanism (FIG. 3) in manner hereinafter explained in connection with FIG. 7. The ejection mechanism includes a stationary slide surface formed by a polytetrafluoroethylene pad 63 which is stuck on a flanged tube 64 supported by a stainless steel bellows 65 within the chamber 16 similarly to the parts 43, 44 and 45. The lower end of the tube 64 is coupledto a pipe 66 which leads through a shut off valve 66A to a source of compressed air in the control unit. Within the centre of the pad 63 is a central circular hole 67 (FIG. 1) forming a pressure port which is 'in register with the ring of smoke ports in the head and is therefore successively brought into communication with the holders 19 as the head 18 rotates. A ring of part spherical cam surfaces 68 is mounted on the underside of the head 18 and as the head rotates the cams 68 successively depress rollers 69 and 70 and operate corresponding microswitches 71 and 72. The first time that the microswitch 72 is closed, and after heating of the thermocouple 61 by a cigarette in any one of the holders 19 has cocked the ejection mechanism, as hereinafter explained in the description of the matter shown in FIG. 7, then closing the microswitch 72 releases the ejection mechanism and opens the valve 66A in the pipe 66, thus causing a blast of air to be supplied through the tube 64 to the particular holder 19 which carries the butt which causes the element 61 to respond. This blast is supplied when the smoke port leading to that holder 19 next comes into register with the pressure port 67. The blast of air causes the butt to be ejected from the holder 19 through a chute 102-into a receptacle 103 containing water or solid carbon dioxide where the butt is extinguished.

The empty holder is then charged automatically with a new cigarette 25 from a hopper 73. The cigarettes 25 in the hopper 73 drop down a guide channel 74 to a charging station 75 which may be supplied with compressed air in any conventional manner from. the same source as that fromwhich the pipe 66 is supplied, under the control of the solenoid operated valve 76. The electrical circuit controlling the charging operation is cocked as a result of a signal received from the element 61 as described above in connection with FIG. 7. When the holder which previously carried the butt which caused heating of the thermocouple 61 reaches a position in register with the loading station 75, the switch 71 is closed by a roller 69 riding under a cam 68 and triggers the loading mechanism so that the valve 76 opens and the new cigarette 25 is blown along the station 75 into the holder to recharge it.

It will be seen from FIG. 1 that the pressure port 67 is midway between two smoke ducts 26 when a holder is in register with the charging station 75. It follows that the source of compressed air can never be called upon to provide air pulses for butt ejection and cigarette loading simultaneously.

The newly charged cigarette is lit as soon as the corresponding holder is brought to the smoking position by counterclockwise rotation of the head. Mounted on an adjustable bracket 77 at the smoking position is a ceramic gas burner 78 which is continuously supplied with gas through a pipe 79. The shape and disposition of the outlet nozzles of the burner 78 and its aeration are such that it burns continuously with a substantially planar flame 80, the flame being tangential to the circle traced out by the tips of new cigarettes. As a puff is taken at the smoking position through the new cigarette the tip of the cigarette is just touching the flame 80 and the cigarette is lit. In subsequent revolutions of the head after. the cigarette has at least smouldered for one revolution, the tip of the cigarette will be spaced sufiiciently far from .the flame 80 to be substantially unaffected by the heat of the flame.

The electronic circuit controlling the ejection and recharging mechanisms is illustrated in FIG. 7. Upon response of the thermocouple 61 a signal is passes through DC coupled amplifier 81 and a schmitt trigger 82 to a relay amplifier (not shown) which amplifies the signal from the schmitt trigger 82 sufficiently to energize the intermediate relay 83, the contacts 84 of which close, starting a 0.75 second short duration timer 85, which effectively holds the voltage from the thermocouple 6] for a predetermined time, thus cocking the ejection mechanism. If while this timer is still operating the ejection microswitch 72 is operated and closed the signal is passed to another 0.3 second short duration timer 86 which, for the 0.3 second period energizes a relay amplifier (not shown) which amplifies the signal from the timer 86 sufliciently to energize the associated relay 87. Operation of this relay closes the switch 88 and energizes an ejection slave relay 89 which in turn closes switches 90 and 91. Closure of the switch 91 causes the solenoid operated valve in the pipe 66 to open and allows a pulse of compressed air to be passed out through the tube 66 and tube 64 to eject the butt to be ejected from holder 19. At the end of the 0.3 second period when the timer 86 stops, the switches 88, 90 and 91 reopen and the shutoff in the pipe 66 recloses. When the switch 90 closes it energizes electromagnetically actuated stepping switch 92 which starts one or other of four long duration timers 93. The purpose of having a bank of four timers 93 is that at any one time the element 61 may have responded up to four times before the holder carrying the butt causing the first response may have reached the charging station 75 and the circuit must be able to memorise the requirement of up to four holders requiring recharging with a new cigarette. When one of the timers 93 stops, it actuates an Eccles Jordan circuit 94 which in turn passes a signal through a pulse detector and amplifier 95 to start a 0.75 second short duration timer 96. if during the operation of this timer 96 the charging microswitch 71 closes, a signal is passed to a further 0.3 second short duration timer 97 which energises a relay amplifier and relay 98. This relay in turn closes a switch 99 which energises a heavy duty relay 100 to carry the current required to operate the electromagnetic valve of the pneumatic loading mechanism 75. Energization of the relay 100 closes switch contacts 101, which cause openings of the valve 76 for 0.3 seconds until the timer 97 stops, and thus provides a 0.3 second air blast to blow a fresh cigarette along the charging station 75 into the holder in register with the station.

The "Schmitt trigger hereinbefore referred to is a circuit of the type first described in an article by O. H. Schmitt in the Journal of Scientific instrumentation" for 1938, at page 24. The Eccles-Jordan" circuit is a circuit of the type described in Basic Electronics," published by Dover Publications, Inc. of New York, in 1963.

lclaim:

l. A cigarette smoking machine comprising a smoking head, means for continuously rotating said smoking head about a vertical axis, a ring of cigarette holders mounted on said head for rotation therewith and extending substantially radially outwards therefrom, parts of said head defining smoke ducts therethrough, one of said smoke ducts being in communication with the interior of each holder, a vacuum port positioned to register for a predetermined period of time with each of said smoke ducts in turn during rotation of said head, and 5 means for applying a predetermined vacuum to said vacuum port to draw a puff through said cigarette holders, and through cigarettes mounted in said holders in use, in turn.

2. A machine according to claim 1, further comprising a first stationary slide surface, parts of said surface defining said vacuum port therein, a first annular surface of said head adapted to sweep over said slide surface 'during rotation of said head, and parts of said annular surface defining openings leading to said smoke ducts.

3. A machine according to claim 2, including a stub ejecting mechanism, said mechanism comprising a second stationary slide surface adapted to be swept by said first annular surface upon rotation of said head, parts of said second slide surface defining a pressure port therein whereby said pressure port is successively brought into communication with said smoke ducts during rotation of said head, and means for applying pulses of air pressure to said pressure port whereby the butts of burnt cigarettes can be ejected from said holders by said air pressure pulses applied to corresponding ones of said smoke ducts through said pressure port.

4. A machine according to claim 3, wherein said stub eject- LII ing mechanismalso includes a butt length sensing element, means mounting said element adjacent said ring of holders whereby said element senses a passing cigarette butt when, but only .when said cigarette has burnt down to a predetermined length, and means responsive to said sensing for causing said element to trigger said means for supplying a pulse of air pressure to said pressure port when the smoke duct leading to the holder carrying said cigarette but is next in communication with said pressure port.

5. A machine according to claim 1, wherein each of said holders incorporates a flexible annular washer adapted to receive a cigarette as a push fit to provide a seal around said cigarette in said holder.

6. A machine according to claim 5, wherein said annular washer is readily removable from said holder for replacement by a washer having at least a different internal diameter to accommodate a cigarette of a different diameter.

7. A machine according to claim 1, incorporating a gas burning lighter for lighting fresh cigarettes fitted to said holder, said lighter providing a substantially vertical planar flame tangential to, and radially spaced outwards just beyond the circle traced out by the tips of new cigarettes fitted to said holders.

8. A machine according to claim 1, further comprising a chamber over which said head rotates, and means mounting said vacuum port in said chamber whereby said smoke ducts open into said chamber during substantially the whole of the period in which they are not in communication with said vacuum port during rotation of said head.

9. A machine according to claim 1, wherein said means for supplying vacuum to said vacuum port includes control means restricting the supply of said vacuum to said vacuum port to a period in which the whole cross-sectional sectional area of the smoke duct is in communication with a constant area of said vacuum port.

10. A machine according to claim 9, wherein said control means includes cams, means rotating said cams synchronously with said smoking head, a conduit through which vacuum is in use supplied to said vacuum port, a shut off valve in said conduit, and means responsive to said cam controlling said shut off valve.

11. A machine according to claim 9, wherein said vacuum port is elongated in the direction of relative movement between said head and vacuum port.

12. A machine according to claim 1, incorporating a cigarette loading mechanism, said mechanism comprising a magazine for cigarettes, a guide adapted to register in turn with said holders, means for blowing cigarettes one at a time from said magazine along said guide into an empty holder in register with said guide, and means for energizing said cigarette blowing means pneumatically.

13. A machine according to claim 12, further comprising a cigarette stub ejecting mechanism adapted to be energized by air pulses, a common compressed air supply system for both said cigarette loading mechanism and said cigarette butt ejecting mechanism, said two mechanisms being so synchronized with rotation of said head that their requirements of air pulses from said common supply system are at all times out of phase with one another.

14. A machine according to claim 1, wherein said means continuously rotating said head incorporates a spring loaded coupling having input and output members, and means for overriding said coupling upon subjection to excessive relative torque between said input and output members greater than that necessary to drive said head normally.

15. A machine according to claim 14, further comprising a magnet carried by one of said input and output members, a reed switch carried by the other of said input and output members, and a valve through which vacuum is applied to said vacuum port and adapted to be controlled by said reed switch, said magnet being carried adjacent to said reed switch and operating'in such a manner that said valve can be opened at intervals under normal operation only when said coupling is properly engaged.

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