Patent GB-483469-A (GB)
Title: Improvements in apparatus for dry cleaning
IPC: D06F58/30
Filed: 1936-10-12
Abstract: <PICT:0483469/III/1> <PICT:0483469/III/2> An apparatus for removing solvent from clothes after dry-cleaning with an inflammable solvent, such as the process described in Specification 483,542, consists of a drying chamber containing an agitator, means for passing air therethrough at a temperature governed by a thermostat, means to render the thermostat inoperative, whereby the air is heated to a higher temperature, and a time control limiting the duration of the heat periods.  The bulk of the solvent is removed at a temperature below the flash point thereof.  An apparatus for use with solvents having a flash point above that of atmospheric temperature, consists of a casing 10, Fig. 5, provided with a perforated tumbler 11 rotating in an inner casing 12, a suction fan 32, and an insulated air heater 15 which is divided by a partition 26 to form two chambers 14, 141 each provided with independent coils of steam pipes 27, 28. Air is drawn by the fan through openings 17, 18, provided with dampers 19, 20, and passes over one or both steam coils into the inner casing and then through the tumbler to an exit 30.  Air is prevented from passing around the casing by a wiping member 138 mounted on the inner drum.  A safety air vent 78 provided with a damper 79 is provided which is open when the fan is not working. The admission of steam to the coils is controlled by a valve operated by a thermostat mounted in the upper part of the casing. In operation, the clothes after treatment with hydrocarbon solvent of flash point about 140 DEG  F., are inserted in the tumbler through a door 13, the suction fan is started, and the tumbler is then rotated.  Air is drawn through the vent 78 and also through the lower vent 18 and over steam coils 27 controlled by the thermostat set at about 135 DEG  F. After a pre-determined short period, dampers 18 and 78 are closed and damper 17 is opened, the steam valve controlled by the thermostat closes, rendering it inoperative, and steam is admitted directly from a main to the coils 28.  Air is drawn over these steam coils and enters the tumbler at about 250 DEG  F.  After a short period, the steam is shut off, damper 19 closes and damper 20 opens, whereby air at the thermostatically controlled temperature is admitted, cooling the clothes.  In apparatus for use with a solvent the flash point of which is below atmospheric temperature, e.g. 90 DEG  F., both heating and cooling coils are used.  An upper coil box 200, Fig. 18 (shown in part), is divided into inner and outer steam coil chambers 205, 206, provided with an undampered air opening 208.  A lower cooling box 201, is provided with a continuous cooling coil 207 and an undampered opening 209.  The admission of heated or cooled air to the tumbler is controlled by a swinging damper 203, the position of which is operated by an air compressor motor 211 co-operating with a series of diaphragm valves operating at different pressures, one of which is controlled by the thermostat.  In either form of the apparatus the dampers, fan, and tumbler are all controlled automatically, and the timing apparatus for the two heat periods and the cooling period is controlled electrically and interlocked with the mechanical controls together with safety devices, and signal lamps showing the start and termination of the three stages.  The safety devices used prevent (1) rotation of the tumbler and the closing of air vent damper 79 before the fan is running, (2) rotation of the tumbler while the charging door is open.  The dampers are opened and closed by an electric synchronous motor, which moves in half-turns through two electric timing controls which govern the low and high heat periods.  The half-turn motor P, Fig. 16, is of the single phase squirrel cage type having a stator connected between one side of the power line and a commutator ring P3, which forms part of a switch.  The switch comprises a brush P2 rotating in synchronism with the rotor.  An <PICT:0483469/III/3> <PICT:0483469/III/4> outer commutator concentric with P3 consists of segments P4, P5, P6 and P7; P5 and P7 being connected through members P8, P9.  When current passes to P4 or P6 a half-turn is initiated, as soon as brush P2 rides off P5 or P7 and on to P4 or P6 the motor stops. The timing control consists of a motor T2 in shunt with power lines L1, L2 through a movable switch 170 normally held against a contact 171 by a spring 172.  The motor is energized by a main switch B.  The rotor of the motor is geared to a friction disc 174 driving a large disc 175, the axis of which is attached to the reciprocatory armature 177 of an electromagnet T1 connected to the circuit of motor T2.  When the switch B is closed, the disc 175 is brought into engagement with the disc 174 and with a friction disc 178.  This disc is mounted on an axis 179 which drives a timing disc 181 calibrated in minutes.  When the disc 181 rotates to its pre-set position, a spring 188 is wound up, and an arm 184 contacts with a lug 185 mounted on the switch arm 170 when the motor circuit is broken at 171, L1P being connected to L1, Fig. 16, and the motor stops.  Switch B is then opened whereby magnet T1 is de-energized and disc 175 is drawn downwards by a spring 180.  The spring 188 then returns the arm 184 to zero-position on the dial, and a spring 172 bring the switch arm 170 to contact 171, completing the cycle.