Patent GB-953676-A (GB)
Title: Improved automat for heat treatment and delivery of food-stuffs
IPC: G07F9/10
Filed: 1962-02-22
Abstract: 953,676. Dispensing articles. HUSQVARNA VAPENFABRIKS A.B. Feb. 22, 1962 [Feb. 25, 1961; March 13, 1961], No. 7005/62. Heading A4T. [Also in Division G4] An automatic machine supplying articles of food from a temperature controlled container has electrically controlled transport means for moving articles from the container to an oven and from the oven to a delivery point, the oven being heated by a thermionic tube micro-wave generator the current supply to the cathode heater of which is controlled by demand for the articles and the anode voltage supply of which is controlled by the transport means. As described the machine cooks and dispenses sausages one at a time in response to a coin actuating mechanism. The sausages are each hermetically wrapped in plastic foil and are carried side-by-side between perforated tapes 1 of tough cardboard as shown in Fig. 2. The resulting band of sausages is wound into a drum and is mounted to rotate on a spindle 3 in a refrigerated container 4 as can be seen in Fig. 1. The end of the band is passed over an idler wheel 5 and the tapes 1 are fed between motor driven sprocket wheels 6 and bearing wheels 7. As shown in Fig. 3 each wheel 6 has sprockets to engage the perforations in the tapes 1 and the associated wheel 7 has a clearance groove 9 for the sprockets and transverse grooves 11 which allow clearance for diametrically opposed knife blades 10 on the sprocket wheel. For each half revolution of the wheels one sausage is advanced to be severed from the band and the next sausage is driven into position in readiness for the next order. When a sausage has been severed from the band it falls on to the presented one of four radially directed shelves 25 frictionally pivoted between arms 24 on the door 16 to a dielectric oven 12. A trap 21 is also pivoted on the door 16 and in the rest position shown, the door is held open by a spring 17 so as to admit the sausage to the oven. The trap is also held open against the action of a closing spring by an abutment 22. As the sausage falls a solenoid 18 is energised to pull door 16 shut, the trap 21 closing of its own accord. The sausage is now offered into the oven on the shelf 25 and a motor 29 mounted on the bottom of the door 16 drives an eccentric 28 which in one revolution moves the pivoted arms carrying the shelf downwards into the oven and back again in a time sufficient to heat the sausage. At the end of its revolution the eccentric releases solenoid 18 and the door 16 and trap 21 open. As the door opens, catches mounted inside the oven engage the bottom of shelf 25 to rotate it by a quarter of a revolution which precipitates the sausage through the trap 21 into a shoot 32 for transportation to a delivery point. A power unit 15 and a cooling fan 14 are provided for the micro-wave generator 13 which preferably employs a magnetron the cathode of which is heated to an operational temperature for 5 to 10 seconds before a sausage is fed from the storage container and before the oven is switched on by connecting anode voltage to the magnetron. Anode potential is controlled by contacts which make and break as the oven door opens and closes. Heating current for the cathode is maintained for 2 or 3 minutes after each delivery to hold the magnetron available without need of a heating up period during periods of heavy demand. The oven 12 and shelf 25 may span a number of different articles mounted in the same manner as the sausages in drums carried side by side on the spindle 3, each drum having its own feeding mechanism and driving motor. Instead of being wound as a drum the bands of articles may be folded in layers in containers below the oven and be lifted out by a feeding mechanism from above. In this arrangement the storage compartment may be made detachable and mounted on wheels so that it may be loaded into the machine with a ready packed supply of articles. An alternative embodiment is shown in Fig. 4, where the band of articles may be mounted on a vertical axis by being wound on a cylinder 64 raised from a carriage plate 66 as seen in Fig. 5. A handle 65 allows the band to be carried on the plate 66 and loaded into the machine to rotate on rollers 67. A number of such drums may be mounted one above the other. Access to the machine is by way of a hinged door 59 in the insulated wall of the storage compartment. In this embodiment articles are dispensed by means of a three toothed roller 43. Actuated by a coin freed mechanism the roller advances one article and stops in a position which aligns a slot 45 in its driving tooth with a knife blade 49. A crank mechanism then reciprocates the knife blade on a slide rod 50 to sever the article from the band for delivery to the oven by way of a shoot 48 the entry of which into the oven may be closed by a trap door. Two feeding rollers may be employed to engage the articles between them, one of the rollers driving an endless spring tensioned conveyer belt to hold each article securely in position; see Fig. 6 not shown. The feed rollers provide an insulated closure for the storage compartment. Transport of an article within the oven may be by means of a wheel with two diametrically opposite pockets into one of which the article is deposited and moved through a half circle to an exit shoot from which the other pocket retreats to take up a position below the entry shoot. Instead of moving the article about in the oven to obtain an even exposure rotating blades may be employed to scatter the electro-magnetic field. Control circuit. A control circuit for a machine of the kind shown in Fig. 1 is illustrated in Fig. 7. Motors M1 and M2 dispense articles from associated storage compartments under the control of interlocked push buttons T1 and T2 connected by permission of a coin mechanism operating contacts S1. The cathode heater 13 of the micro-wave magnetron generator is kept warm by a small filament current delivered over transformer TR and back contact 02 of a relay Re1 during idle periods. When a coin is deposited contacts S1 operate and over diode D2 operates relay Re1 which locks up with its contact K11 and with contact 02 connects full heating current to the filament 13. The pre-selector button T1 is assumed to have been operated in choice of the goods dispensed by motor M1 and by release of its contacts K3 introduces a resistor R1 into a charging circuit for capacitator C1 the voltage for which is variable at potentiometer P1. After a delay of 5 to 10 seconds, which it is assumed is sufficient to heat the cathode to operating potential, capacitor C1 has charged sufficiently to ignite tube G1 which in its anode circuit operates relay Re2. Contacts 03 of Re2 complete the circuit for motor M1 selected by button II and the feeding mechanism advances to cut an article from the band. Cam contacts K5 and K6 on the motor operate solenoid DM to close the oven door, after the article has been deposited, and to start motor M3 which oscillates the article within the oven by means of an eccentric. Solenoid DM operates off normal contacts K11 to K14 to connect anode potential to the magnetron and to disconnect the filament heat circuit while the magnetron is being driven. When the eccentric has advanced by half a revolution it actuates contacts K9 and O1 to extinguish the glow tube G1 and initiate slow release of relay Re2. When Re2 falls back M3 stops but capacitor C1 recharges over resistor R1 to re-ignite tube G1 and re-operate Re2 allowing M3 to start and drive its eccentric the remainder of its revolution at the end of which its cam contacts break. Mo for M3 now halts and solenoid DM releases to open the oven door and precipitate the article towards delivery. With contacts K11 of DM now normal and relay Re1 still operated the anode potential is removed to switch off the oven and full filament current is supplied over heating resistor R3 of a bi-metallic contact S2. By this means the magnetron is held in instant readiness to deal with an order for a period of 2 to 3 minutes after which contacts S2 break to release Re1 and restore the small warming filament current and to permit the initial heating period as and when an order is received. The use of different resistors R1 and R2 associated with the push buttons T1 and T2 allows the different articles they select to spend different lengths of time in the oven since they govern the time taken to re-ignite tube G1 and, consequently, the time for which motor M3 is at rest during the active part of its cycle.