Patent GB-1025083-A (GB)
Title: Fabric drying machines
IPC: H01T23/00
Filed: 1962-09-26
Abstract: 1,025,083. Spin and tumbler driers. BORGWARNER CORPORATION, and J. D. ROBBINS. Sept. 26, 1962 [Oct. 3, 1961], No. 36808/65. Divided out of 1,025,081. Heading F4G. A spin and tumbler drier of a dry-cleaning apparatus comprises a rotatable perforated basket 18, Fig. 5, within a fixed tub 11 which is adapted to be rotated at high speed for spindrying by an electric motor M, Fig. 6 (not shown), through a two-speed gear T and belt drives 42, 22. The basket 18 is also adapted to be rotated slowly for a tumble dry when a heater 73 within the tub 11 and an air-circulating fan 32 driven by a belt 63 are also in operation. A condenser 77 provided with cooling water is also provided in the lower part of the tub to condense the solvent vaporized during this drying operation which then drains away. Air inlet and exhaust valves 83, 84, Fig. 6 (not shown), are provided in the tub 11 to flush away solvent vapour left at the end of the drying operation through a blower and ventilating ducts. The door 17 of the tub 11 has a lock mechanism which is electrically controlled so thatthe door cannot be opened during the operating cycle of the machine. A cleaning and drying cycle of operations of the machine may be started by a coinoperated mechanism and controlled automatically thereafter by a timer motor 285, Fig. 29 (not shown), operating cams through a step-by-step mechanism to actuate sequentially switches controlling the operation of the various valves and other components of the machine. Two sub-interval timers are also provided, the first of which provides a drying time delay in the event of an interruption of air flow during the dry cycle due, for example, to the fan belt being broken or loose or excessive loading of the basket. The second sub-interval timer provides a delay of the main timer during a "Pre-dry" period and " Timed dry pause " period. The drying cycle initiated after the various cleaning operations by the timer 285 is continued automatically through the following operations: Extract and heat period.-The basket is rotated at high speed for 2 minutes with the heaters " on " and the fan " off." The drain valve is open, and the operation is under control of " high," " low " and " safety " thermostats 284-282. Drop load period.-Motor and heater are deenergized for ¢ min. to allow the clothes to fall to the bottom of the basket for subsequent re-distribution. First timed dry period.-Heaters and fan energized and basket rotated at slow speed for 4 mins. Condenser water valve is opened as is also the drain valve. Timed dry pause period.-Operation is as before for a period of 12 mins. but under control of a sub-interval timer #2, the main control timer 285 being de-energized but advanced at 5 sec. intervals by the sub-interval timer. Second timed dry period.-The main control timer takes over again and continues for 2¢ mins. as before, the sub-interval timer # being switched off. Automatic dry pause period.-The control timer is switched off but basket is rotated slowly with heater and fan on until temperature reaches 145‹ F., when timer is re-started. This period is of 1 min. minimum but depends upon the time taken to reach the desired temperature, when the heaters are switched off. During this period also the sub-interval timer #1 will operate in the event of loss of air flow due to loose or broken fan belt, excessive loading of basket, blocking of fan screen, or failure of control thermostat 282. Safety thermostat 284 switches off heater, fan and control timer, but energizes sub-interval timer #1 which steps main control timer around at 5 sec. intervals until the air flow condition is corrected or a period of 12 mins. has elapsed. Dry no-heat period.-Basket is driven slowly for 2¢ mins. with heaters " off " and fan " on." Cool down period.-Basket is rotated slowly with fan " on " and ventilating air inlet and exhaust valve 83, 84 for the removal of the solvent vapours. Completion of drying cycle.-The main control timer 285 operates for ¢ min. to condition a circuit for energizing a door-release solenoid so that the operator can open the door of the machine.