The Design of an Automated Syringe-Type Smoking Machine

An automated smoking machine, and improved associated equipment, has been described. The automatic portion consists of a "string cut-off" technique which instantly and accurately stops the puffing action on cigarettes. This is achieved by an electronic sequence that deactivates three-way solenoid valves and vents the smoking train to the air at the syringe. Solenoid deactivation is achieved through the use of microswitches and relays. An automatic puff-counting unit records the number of puffs taken on the cigarettes on each port. The counters are pulsed by a signal generator set for 5 pulses per second. The generator is activated by a 2-second cam and microswitch attached to the 4-second cam that cycles the smoking machine. Constant puff volume and puff duration are maintained by use of individual syringe eccentric cams that allow precise volume adjustment on each port and solenoid valves that serve as intake and exhaust valves and provide positive action. The solenoid valves are activated by the 2-second cam and microswitch that is synchronized with the puffing downstroke of the syringe. The 2.0 AA± 0.2-second puff is precisely obtained through the machine's variable speed controlled gear driven electric motor. This feature yields a stable volume and duration regardless of the resistance of the cigarettes. The level of precision obtained previously on the O'Keeffe and Lieser machine was reduced by one-third by the automation developments described in this paper.