US3426555A

US3426555A - Dry cleaning

Info

Publication number: US3426555A
Application number: US378162A
Authority: US
Inventors: Charles E Mccutcheon Jr
Original assignee: CHARLES E MCCUTCHEON JR
Current assignee: CHARLES E MCCUTCHEON JR
Priority date: 1964-06-26
Filing date: 1964-06-26
Publication date: 1969-02-11
Anticipated expiration: 1986-02-11

Description

Feb. 11,1969" Filed June 26, 1964 c. E. M CUTCHEON,

DRY CLEANING Sheet of :3

ii FIGS.

4M, $1.4 mm, aw,

Feb. 11, 1969 c E. MOCUTCHEON, JR 3,426,555

DRY CLEAN I NG 3 of s,

Sheet Filed June 26, 1964' C. E. M CUTCHEON, JR

DRY CLEANING Feb. 11, 1969 Filed June 26,

Sheet Feb. 11, 1969 c. E. M CUTCHEON, JR 3,426,555

' DRY CLEANINQ Filed June 26, 1964 Sheet of 5 FIGB.

MOTOR- 425 RPM.

MOTOR43RP:M.

ACUUM S ITCH VACUUM B AIR BY-PASS United States Patent 3,426,555 DRY CLEANING Charles E. McCutcheon, Jr., Highway and Lucky, Fayette, Mo. 65248 Filed June 26, 1964, Ser. No. 378,162 US. C]. 68-12 18 Claims Int. Cl. D06f 33/02 29/02 ABSTRACT OF THE DISCLOSURE and its operation is controlled so that a vacuum is drawn in the chamber at the beginning of the cleaning cycle and vacuum is maintained in the chamber during the cleaning and drying cycles of operation. Work is cleaned by loading it into the chamber and sealing the chamber, then drawing a vacuum in the chamber and introducing the evaporative dry cleaning fluid into the chamber. The work is agitated in the chamber and cleaned by the cleaning fluid under a vacuum on the chamber. Then the fluid is drained from the chamber and the fluid evaporated from the work. The used cleaning fluid is reconditioned by a process including the steps of vaporization and condensation of the fluid.

The invention is especially concerned with a so-called closed-circuit dry cleaning system in which the work is cleaned in a chamber or tub which is connected in a closed fluid system adapted to supply a quantity of dry cleaning fluid to the chamber for a cleaning cycle, discharge used fluid from the chamber after completion of the cleaning cycle, and recondition the used fluid (i.e., separate therefrom residuals picked up in the cleaning operation) to provide fresh, clean, pure fluid for the next load. This reconditioning or recovery of the used fluid is carried out during the drying cycle, which follows the cleaning cycle, and may continue for a time after the completion of the drying cycle.

Among the several objects of the invention may be noted the provision of a system such as described which enables effective and economical utilization of a modern, fast-acting, odor-free dry cleaning solvent or fluid, such as for example that sold under the trademark Valclene 1 by E. I. du Pont de Nemours & Company of Wilmington, Del. This is understood to be a fluid consisting primarily of a fluorocarbon such as that sold by said company under the trademark Freon 113 plus a small amount of a detergent. Other fluorocarbon dry cleaning solvents or fluids such as those disclosed in Patent No. 3,042,479 may also be used in the practice of the present invention. Such dry cleaning solvents or fluids are relatively expensive, and economical utilization thereof necessitates operation with minimum loss of fluid (which, being relatively highly volatile, is relatively difficult to contain) and with substantially complete recovery of used fluid. The system of this invention enables utilization of such fluid with minimum loss, featuring cleaning of the work under vacuum in a vacuum chamber, as distinguished from cleaning under atmospheric or higher pressure as heretofore. This tends to preclude the possibility of leakage of fluid from the chamber and inhibits loss of fluid, the tendency being for air to be drawn into the chamber rather than for fluid or its vapor to escape from 3,426,555 Patented Feb. 11, 1969 the chamber. A corollary of this is that in drawing a vacuum in the chamber, vapor is drawn off from the chamber and delivered into the fluid system for recovery. Among further objects may be noted the provision of such a system in which the overall cleaning and drying time may be kept to a minimum, drying also occurring under vacuum in the chamber for rapid evaporation of fluid from the work; the provision of such a system attaining uniform dryness of work on each cycle and substantially complete evaporation of fluid from the work to avoid loss of fluid; and the provision of such a system attaining substantially complete recovery of fluid including recovery of vaporized fluid entrained in air which may be drawn into the system. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions and methods hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated:

FIG. 1 is a front elevation of a machine of this invention;

FIG. 2 is a rear elevation of the machine;

FIG. 3 is a left side elevation of the machine with a left side panel removed, taken on line 3-3 of FIG. 1;

FIG. 4 is a right side elevation with a right side panel removed, taken on line 44 of FIG. 1;

FIG. 5 is an enlarged longitudinal cross section of a so-called stripper used in the machine;

FIG. 6 is a diagrammatic flow diagram of the machine;

FIG. 7 is a diagram showing the electric circuitry of the machine; and

FIG. 8 is a time chart showing the sequence of operation during a typical dry cleaning cycle.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, a dry cleaning machine of this invention is shown to comprise a vacuum chamber 1 having a rotary perforated drum or basket 3 therein for receiving a load of items to be cleaned. Chamber 1 may also be referred to as a wash tub (the items or work being washed therein). Basket 3 may also be referred to as a tumbler, since it is adapted to tumble the 'work. At 5 is indicated a storage tank for dry cleaning fluid to be supplied to the chamber or tub 3 for dry cleaning of the work by solvent action. After the work has been cleaned in the tub, the used dry cleaning fluid is discharged from the chamber or tub I and recovered for subsequent reuse by means of a recovery system generally designated 7 in FIG. 6. The recovery system 7 comprises a still 9 for vaporizing the used dry cleaning fluid, and a series of

condensers

11, 13 and 15 for condensing the vaporized dry cleaning fluid, the resulting condensed. fluid (the condensate) being ultimately returned to storage tank 5 for reuse. At 17 is indicated a vacuum pump for evacuating the chamber or tub I at the start of a cleaning cycle, a vacuum being maintained in the chamber during the washing and drying of work therein. The discharge side of the vacuum pump 17 (which is in effect a compressor) is connected to the still & and provides a positive pressure in the still for pressurized delivery of vapor boiling off in the still through the recovery system 7.

At 19 is indicated a frame which carries the various elements of the machine. The chamber or tub 1 comprises a cylindricalbody mounted in horizontal position toward the front of the frame, and extending in front-to-rear direction in the frame. It has front and rear end heads constituted by

plates

21 and 23 mounted in the frame. Plate 21 has an access opening 25. On the front of the frame is a front panel 2 7 having an opening 29 aligned with opening 25. A door D is hinged at 30 on panel 27 for closing access opening 25. A solenoid-operated latch for the door is indicated at DL. At DS (see FIGS. 1 and 7) is indicated a door-actuated switch which is actuated when the door is closed to complete a circuit for the door latch DL and for a coin control to be described. At 31 is indicated a lamp which is energized to signal that the door is unlatched or open. The door has a gasket 32 engageable with plate 21 around opening 25 with a sufficiently tight seal to prevent leakage of air into chamber 1 when the door is closed and while the chamber 1 is under vacuum.

The drum or basket 3 is rotary in chamber 1 on the horizontal axis of the chamber, being mounted at its rearward end on the forward end of a shaft 33 which extends through a seal 34 mounted on rear plate 23 of the chamber. Basket 3 has an access opening 35 at its forward end for loading of the work therein and removal of the work therefrom. It carries an electrical resistance heating element 37 for heating work in the basket during the drying of the work, and a thermostatic switch 39 for controlling the operation of the latter. Slip rings 37a provide for electrical connection to the heater 37, and slip rings 39a provide for electrical connection to the thermostatic switch 39. As shown in FIG. 7, the latter is in series with the coil 41 of a relay which has contacts 43 in series with the heater 37. The dry cleaning fluid which it is preferred to use in the machine has a boiling point of about 11'7-1 18 F., and switch 39 is set to close at about 136 F. and to open at about 140 F. During the drying cycle, the chamber or tub 1 is under a vacuum, which reduces the solvent boiling point, and thus the clothes are dried by boiling out the solvent at relatively low temperatures.

A pulley 45 is mounted on the rear end of shaft 33 and the pulley and shaft are adapted to be driven alternately by

motors

47 and 49. Motor 47 is a three-quarter horsepower motor having a shaft 47a projecting from both ends. On one end of shaft 47a is a pulley 50 coupled to pulley 45 by a belt 51. Motor 47 is adapted to drive shaft 33 at a speed of about 425 rpm. via the belt and pulley drive 50, 51, 45 for spindrying. Motor 49 is a two-speed one-quarter horsepower motor and is connected by a belt and pulley drive 53 to the other end of shaft 47a of motor 47. Shaft 47a thus acts as a jack shaft in a double speed reduction system such that motor 49 is adapted to drive shaft 33 at a so-called tumble speed of about 43 rpm. or a so-called distribution speed of about 63 rpm. When motor 47 is operating, a clutch (not shown) uncouples the motor 49 from the double reduction system.

The storage tank for the dry cleaning fluid has a partition 55 (see FIG. 6) which divides it into a so-called wash solvent section 57 and a so-called storage section 59. The wash solvent section 57 receives condensed dry cleaning fluid (solvent) from the condenser 11. This fluid may contain some water. The water, being lighter than the dry cleaning fluid, will float on top of the latter in section 57. As section 57 becomes filled, the water at the top and some of the dry cleaning fluid spills over the top of the partition 55 into section 59 of the tank. Thus, a substantially waterfree supply of dry cleaning fluid is provided in section 57. Section 57 holds about thirteen gallons of fluid, for example, and approximately eleven gallons, for example, are discharged during a cleaning cycle. The fluid is adapted to flow by gravity from section 57 of tank 5 through a conduit 61 to the chamber 1. A wash solvent solenoid valve 63 in conduit 61 controls flow of fluid from tank section 57 to the chamber.

In the course of operation of the machine, used dry cleaning fluid is discharged from chamber 1 to still 9. During this phase of operation, a solenoid valve 65 below storage tank 5 opens to equalize the level of fluid in

sections

57 and 59 of the tank. This equalization of the fluid levels insures that sufiicient fluid will be available in section 57, after distillation and condensation of the used dry cleaning fluid, to provide a copious overflow of solvent across the partition between the two sections, thereby transferring water collected in section 57 over to section 59. A manual drain valve 67 provided for section 59 of the tank 5 is periodically opened to remove the water from section 59 (some dry cleaning fluid may also be removed at this time). Such dry cleaning fluid as may be removed from section 59 can be transferred to the still 9 and distilled therein for recovery.

A float assembly 69 in tank 5 comprises a magnetic float 71 and lower and upper reed switches 73 and 75, respectively. Switch 73 is normally closed and opens when the level of fluid in section 57 of the tank drops and the floating magnet comes into proximity with the switch. Switch 73 is in series with the solenoid valve 63 and deenergizes the solenoid when the level in the storage tank drops to a predetermined level, such as about two inches above the bottom of the tank. The upper switch 75 is normally open and closes when the storage tank solvent level rises in section 57 and the float 71 rises. FIG. 6 shows section 57 full and switch 75 closed. Switch 75 opens if the level of fluid in section 57 falls below that required for a cycle, and takes the machine temporarily out of service until an adequate supply of fluid transfers from the still to the storage tank. Switch 75 is closed at the start of any operation of the still 9 during (and after) the previous cycle.

The suction inlet of vacuum pump 17 is in communication with chamber 1 via a conduit 77 having a filter 79 therein. A vacuum gauge 81 may be provided for reading the vacuum drawn in the chamber. The pump 17 is a conventional refrigeration compressor, for example, capable of drawing a vacuum of at least 28 inches of mercury in the chamber 1 .and having a discharge pressure of about 10 p.s.i. Operation of the pump 17 simultaneously produces a vacuum in chamber 1 and a pressure downstream from the pump in the recovery system 7, this pressure being utilized to transfer vapors from still 9 through the recovery system as explained hereinafter.

The discharge outlet of pump 17 is connected by a conduit 83 to the still 9, a pressure relief valve 85 being provided in conduit 83 to limit pressure entering the still to a maximum of 10 p.s.i. An air by-pass solenoid valve 87 in a conduit 89 branching from conduit 83 is open during initial operation of pump 17 at the start of a dry cleaning cycle, s that residual air or other gases in chamber 1 which do not contain dry cleaning fluid to be reclaimed are discharged directly to the .atmosphere. Valve 87 is closed during recovery of used dry cleaning fluid and opens again at the end of the drying cycle. A gauge 91 may be provided for indicating the outlet pressure of the pump 17.

The chamber or tub I is connected to still 9 by a drain line 93 having a solenoid-operated dump valve 95 therein. This valve is opened at the end of the wash phase of a cycle to discharge used dry cleaning fluid from the chamber to the still. Fluid in the still 9 is heated by hot water flowing through a heating coil 97 therein. The ends of the heating coil 97 project through a rear clean-out door 99 (see FIG. 2) and are connected to a suitable source of hot water (not shown). A hot water circulating pump 100 (see FIG. 6) may be provided for circulating the hot water. The clean-out door 99 and the coil 97 are periodically removed for removal of dirt, detergent, etc. which collects in the still. A manually operated drain valve 101 is provided for draining the still. A solenoid valve 103 is provided for starting and stopping the flow of hot water through the coil.

Since the vacuum pump 17 reduces the pressure in chamber 1 below atmospheric pressure, and since the discharge outlet of the vacuum pump is connected to the still 9, there is a pressure differential between the still and the chamber during the cycle. This pressure differential needs to equalize before opening of the dump valve 95 to prevent entry of gases from still 9 into the chamber through the dry cleaning fluid in the bottom of the chamber. For this purpose, there is provided a pressure equalizer conduit 105 between the still and the chamber connected to the latter above the level of the dry cleaning fluid therein, this conduit having a solenoid valve 107 therein. Valve 107 is opened to equalize pressure between the still and the chamber prior to opening of the valve 95 to dump used dry cleaning fluid into the still. A pressure-responsive safety valve 109 is provided to prevent excessive build-up of pressure in the still.

Since the chamber or tub I is under a vacuum during the drying cycle, it must be returned to atmospheric pressure before door D can be opened. For this purpose, a solenoid operated vacuum breaker valve 111 is connected to the top of the chamber, this valve being opened at the end of the drying phase of the cycle to permit atmospheric air to enter the chamber, thus breaking the vacuum in the chamber, and permitting the door 25 to be opened.

At 113 is indicated an exhaust solenoid valve 113 for the chamber or tub 1. This is controlled by a doublethrow door-actuated switch 115, (see FIG. 7), this switch closing to solenoid valve 113 when the door D is opened and closing to a control box generally designated B in FIG. 7 when the door is closed. An exhaust blower or fan 117 connected to the outlet of valve 113 pulls out gases from the chamber 1 when the valve is open. The blower 117 is energized along with valve 113 by operation of the door switch 115. Thus, when the door D is opened, air is circulated through the chamber 1 and residual gases in the chamber are evacuated through the opened valve 113.

During each wash cycle, detergent from a supply tank 1.19 is supplied to chamber 1 via a line 121 having a solenoid valve 123 therein. The chamber is under a vacuum at the time the detergent is supplied, and the detergent supply tank 119 may be located below the chamber and the detergent siphoned through the line 121. The detergent in supply tank 119 can be a detergent-solvent mixture sold under the name Valclene 200 by E. I. du Pont de Nemours & Company which is understood to consist of approximately 80% Freon-type solvent and 20% detergent. About two fluid ounces of this mixture are supplied during each wash cycle. The detergent in the detergent-solvent mixture is either retained to some extent on the work or is deposited in the still 9 during distillation of the used dry cleaning fluid.

Two vacuum switches 125 and 127 are provided in communication with the chamber or tub 1. Switch 125 is a safety switch for preventing operation of the system at less than a predetermined vacuum, being open when vacuum in the chamber is below four inches of mercury, for example, and closed when the vacuum increases to approximately eight inches of mercury, for example. Switch 125 is connected in a circuit with the vacuum pump 17 as explained hereinafter so that the pump is energized when the vacuum drops below four inches of mercury. The vacuum switch 127 functions as a dry sensor, in a manner to be hereinafter explained, to prolong the drying phase of the cycle, if necessary, and to insure that each work load is uniformly dried.

Vaporized dry cleaning fluid (and possibly other fluids) vaporized in still 9 are delivered to condenser 11 via a conduit 128 having a manual control valve 129 therein. The vapors passing through the condenser 11 are at greater than atmospheric pressure. The condenser 11 is a water-cooled tube-in-tube condenser, for example, cooled by cold water passing through a tube 130 under control of a manual valve 131. Positive pressure in still 9 forces the condensed fluid through the condenser 11 and into section 57 of the storage tank 5.

All the vapor may not be condensed in condenser 11 and air saturated with vapor may enter tank 5. This flows via a conduit 133 to a so-called accumulator tank 135 and to the condenser 13 (which is a refrigerated condenser). The accumulator tank 135 floats on conduit 133, that is, it receives saturated air from the storage tank 5 and discharges it in response to pressure conditions in the conduit 133. As pressure in conduit 133 increases due to operation of the pump 17 and the slow passage of fluids through refrigerated condenser 13, the pressure increases in conduit 133 to force the saturated air into the accumulator tank 135. As the vapors u1timately pass through refrigerated condenser 13, the pressure downstream from the accumulator tank decreases, and saturated air exits from the accumulator tank and enters the condenser 13. A normally closed pressure switch 136 in communication with the accumulator tank opens if the pressure therein exceeds four p.s.i. to deenergize the pump 17 as explained later.

Condenser 13 includes two parallel-connected condenser coils 137 and 139 through which the saturated air passes. The vapor in

coils

137 and 139 is cooled by heat-exchange with a refrigerant line 1141 supplied with refrigerant from a refrigeration system including a compressor 145, a condenser 147, a receiver 148 and a themostatic expansion valve 149. The valve 149 is controlled by a thermostat 151. The refrigerant system is adapted to be defrosted by opening a defrost solenoid valve 153 to deliver hot refrigerant to the cooling coils.

As the saturated air passes through the

coils

137 and 139, vapor in the air is condensed and drains through a conduit 155 into a collector 157. A branch conduit 159 connects conduit 155 with the vapor inlet of the condenser 15, which is also refrigerant-cooled and which may be called a stripper. Vapor remaining in the air is condensed in the stripper, in which the air flows upward around a finned portion 161 of refrigerant line 141. Condensate drains from stripper 15 through a line 165 into the collector 1.57. The remaining air, containing at most a minor amount of vapor, passes upward from the stripper through a conduit 167 having therein a check valve 169 for preventing back flow of air into the stripper and a throttle valve 171 for restricting the passage of air from the stripper through the conduit to the atmosphere. Valve 171 also regulates the output of air from the accumulator 135 since it determines the volume of gas which can pass through the

coils

137, 139. Some solvent may condense downstream from the valve 171, and any such condensate is collected in a jar 173. Collector 157 is connected to the still 9 by a conduit 175 having a solenoid operated valve 177 therein which opens when the dump valve 95 is energized thereby to drain condensate in the collector 157 into the still.

As herein illustrated, the machine is coin-controlled, the control box B being a commercially available coin accumulator control meter, such as the Series 5800 Deal- A-Price Coin Accumulator Meter sold by H. Greenwald Company of Brooklyn, NY. Generally, this meter comprises a so-called start switch 181 (which is a doublethrow switch), a stepper switch 183 operated by a stepper coil 184, a so-called homing and bypass switch 185, and a so-called coin bypass switch 186 (see FIG. 7). Associated with the meter is a so-called rejector assembly 187 (see FIG. 7) which includes a coin-actuated switch 189 and a rejector coil 191.

Switch 181 is normally closed on its lower contact as shown in FIG. 7, switch 183 is normally open, and switch is normally closed on its right-hand contact. Switch 189 is normally closed on its upper contact. When a coin is inserted in the meter, switch 189 closes momentarily on its lower contact, sending a pulse of current through stepper coil 184 via switch 75 (which will be closed assuming the level of fluid in storage tank section 57 is up), a manual switch 193 and a manual switch 195. On the first such pulse, switch 185 closes on its left-hand contact. Upon insertion of the proper amount in coin (as set up in the meter), start switch 181 closes on its upper contact, and this institutes a cycle of the machine.

Switch 193 may be manually opened for placing the machine out of service. A signal lamp 197 may be provided paralleling switches 75 and 193 for signalling an open condition of either of these switches, indicating that the machine is out of service. Switch 195 is a defrost switch for the refrigeration system of the machine, adapted to be opened off two upper contacts and closed on a lower contact for this purpose. A signal lamp 199 may be provied paralleling switch 195 for signalling that switch 195 has been thrown for defrosting and that the machine is out of service.

Referring to FIG. 7, electric power supply lines for the machine are indicated at L1 and L2. The motor of refrigerant compressor 145 is connected directly across these lines, and hence is energized continuously as long as lines L1 and L2 are plugged into a service outlet and energized.

A sequence timer or programmer switch unit is indicated generally at P in FIG. 7. This is of a conventional type including a plurality of switches actuated by cams on a camshaft driven by a timer motor. The cams and camshaft are omitted from the drawings; the timer motor is indicated at 201 in FIG. 7. Programmer P is shown to comprise ten double-throw switches S1S10, each having a movable contactor adapted to close from a neutral position on a top contact T or a bottom contact B. Motor 201 is connected between the top contact of switch S and line L1. The movable contactors of switches S1S7, S9 and S10 are electrically interconnected as shown in FIG. 7. The movable contactor of switch S8 is interconnected with the power line for compressor 145 so that current is supplied thereto as long as supply lines L1 and L2 are live. Switch S8 controls heating of the still 9, and operation of the still may continue after termination of a cleaning and drying cycle of the machine.

The motor 201 drives the switchactuating cams of programmer P through 360 during each cycle of operation of the machine to control the sequence of steps in the dry cleaning process. It rotates the cams approximately 8 during each of forty-five 22 /2 second intervals for ap proximately a seventeen minute dry cleaning cycle. A circuit is closed to the timer motor 201 through upper contact T of switch S10 except during the dry sensor operation explained later. The time chart of FIG. 8 shows the closure condition of switches S1S10 on the top T or bottom B contacts of the switches during the respective forty-five 22 second time intervals.

As charted in FIG. 8, the cam for programmer switch S1 is such as to hold the switch closed on its top contact T for the first 22 /2 second interval, and to close switch S1 011 its bottom contact B for the remaining forty-four 22 /2 second intervals, the switch closing back on its top contact at the termination of the complete time cycle.

The cam for switch S2 is such as to hold this switch open for the first sixteen intervals, to close it on its bottom contact at the beginning of the seventeenth interval and hold it closed on the bottom contact through the twentieth interval, to hold it open for the twenty-first interval, to close it on its top contact at the beginning of the twenty-second interval and hold it closed through the forty-second interval, then open it for the remainder of the time cycle.

The sequence for the remainder of the switches will be apparent from the chart.

As noted, switch S1 is closed on its top contact T at the start of a cycle of the machine. The circuitry is such as shown in FIG. 7 that, upon closure of start switch 181 on its upper contact, current is supplied via switch 181 to the top contact of switch S1. The movable contactor of switch S1 is connected to the movable contactor of switch S10, which is closed on its upper contact, and the latter is interconnected with timer motor 201. Accordingly, upon closure of start switch 181 on its upper contact, motor 201 is energized and starts timing out the sequence of the machine. At the end of the first 22 /2 second time interval, switch S1 closes on its bottom contact B, which is supplied directly with current from line L2. This holds motor 201 in operation.

Switch S3 is closed on its bottom contact at the start of a cycle. Both top and bottom contacts of this switch are interconnected with motor 49. With S3 closed on its bottom contact, motor 49 is energized for operation at low speed to drive basket 3 at approximately 43 rpm.

The accumulator tank pressure switch 136 (shown at the bottom of FIG. 7) is connected in series with the coil of a defrost relay R1 across lines L1 and L2. Switch 136 is normally closed at the beginning of each cycle since the pressure in the accumulator tank 135 is less than 4 p.s.i. Thus, the coil of relay R1 is energized to close the associated normally open relay contacts RlA and open the normally closed relay contacts RIB of relay R1. Switch S7 is closed on its top contact T during the first time interval to complete a circuit through the defrost relay contacts R1A to the coil of a vacuum pump relay R2. This closes the normally open relay contacts RZA and RZB to close a circuit to the vacuum pump 17 between lines L1 and L2.

A thermal reset relay R3 has normally open contacts R3A in parallel with a push button switch 203. The relay contacts R3A and switch 203 are interconnected with two thermostatic switches TH1 and TH2 which sense the temperature in the storage tank '5 and in the conduit 93 between chamber 1 and still 9. The thermostatic switches TH1 and TH2 are normally closed and, by closing the push :button switch 203, the coil of relay R3 is energized and contacts R3A close to hold the circuit closed until the thermostatic switches open. Opening of either of the thermostatic switches places a signal lamp 205 in the circuit, indicating that the circuit is open. The thermal reset relay R3 has another normally open set of contacts R3B in series with the bottom contact of switch S8. A normally closed hot water switch 207 is in series with the relay contacts R3B, a normally closed water pressure switch 209 and hot water solenoid valve 103. During the first time interval of the dry cleaning cycle, as well as between dry cleaning cycles, current is provided through the lower contact of switch S8, through the relay contacts R3B, and switches 207 and 209 to the hot water solenoid 103 to open the valve and permit hot water to flow through the coils 97 in the still.

Switch S9 is closed on its bottom contact during the first two time intervals of operation of the timing motor to close a circuit to the air bypass solenoid valve 87 downstream of the vacuum pump 17 so that air and other gases initially pumped from chamber 1 are discharged to the atmosphere. At the end of the first time interval, switch S1 closes on its bottom contact so that line current is received directly by the programmer P. Simultaneously, switch S8 is opened to its neutral position to take the hot water solenoid valve 103 out of the circuit, thereby closing the valve and stopping circulation of hot water in the still. When vacuum in chamber 1 is greater than 4 inches of mercury, vacuum switch closes and this places the coil of a vacuum relay R4 in a circuit from the bottom of the programmer P. The vacuum relay R4 has a set of normally closed contacts R4A in a circuit to the bottom contact of switch S4. A normally open set of contacts R413 of relay R4 is in a circuit to the bottom contact of switch S6.

At the beginning of the third time interval and when vacuum relay contacts R4B are closed, a circuit is com.- pleted from the bottom contact of switch S6 through the normally closed magnetic fill switch 73 in tank 5 and the solenoid fill valve 63, so that dry cleaning fluid is transferred from tank 5 to tub 3. A spark suppressor circuit consisting of a 510 ohm resistor 210 and a 0.1 mfd. capacitor 212 is in parallel with the magnetic switch 73. As long as vacuum is retained in chamber 1, vacuum switch 125 remains closed and relay R4 is energized so that the solenoid valve for filling the chamber can be opened. Should there be leakage into the chamber which prevents its evacuation, switch 125 will not close and dry cleaning fiuid will not be supplied to the chamher. This prevents loss of expensive dry cleaning fluid by evaporation from a leaking chamber. During the third time interval, switch S4 is closed on its bottom contact, but a circuit including this contact is not complete when the chamber has been evacuated, since the relay contacts R 4A are then opened. Should the vacuum in chamber 1 be reduced or lost altogether, switch 125 opens, relay R4 is deenergized and contact R4A returns to its normal closed position. This completes a circuit to the relay R2 to start the vacuum pump. Thus, operation of the relay R4 and its contacts prevents the vacuum in chamber 1 from dropping below 4 inches of mercury any time switch S4 is closed on its bottom contact.

At the beginning of the third time interval in the cycle, switch S9 takes the air bypass solenoid valve 87 out of the circuit to close the valve so that any vapor evacuated from chamber 1 by the vacuum pump 17 is directed to the still 9. This prevents evacuation of dry cleaning solvent vapors from the system.

Switch S7 is closed on its bottom contact at the beginning of the third time interval to close a circuit through the programmer P and the defrost switch 195 to the refrigeration solenoid defrost valve 153 which directs hot refrigerant gases through the refrigeration system for defrost purposes.

Starting with the sixth time interval, switch S8 is closed on its top contact for two increments to energize the detergent solenoid valve 123 and provide detergent to the chamber 1. The switch S8 is opened at the end of the seventh time interval to close the valve 123.

At the start of the tenth time interval, switch S6 closes on its top contact to close a circuit to the solenoidoperaed equalizer valve 107 between chamber 1 and still 9 to equalize the pressure therebetween. At the end of the tenth time interval, switch S4 opens to take the relay R2 out of the circuit. At the end of the eleventh time interval, switch S7 opens to terminate the refrigerator defrost cycle. Also at the end of the eleventh interval, switch S5 closes on its bottom contact, which simultaneously operates the dumping solenoid valve 95, the storage tank equalizing valve 65 and the collector drain valve 177. This discharges the used dry cleaning fluid from chamber 1 into the still 9 and equalizes the level of fluid in the

sections

57 and 59 of the storage tank. Also, any dry cleaning fluid in collector tank 157 from the previous cycle is discharged into the still 9.

At the start of the fifteenth time interval, switch S3 closes on its top contact to close a circuit to motor 49 and increase the speed of the basket 31 to approximately 63 r.p.m., i.e., its distribution speed. At the start of the seventeenth time interval the swich S2 closes on its bottom contact B to energize the high speed motor 47 to turn the basket 3 at approximately 425 rpm. until the end of the twentieth time interval. This high speed spin of the basket extracts most of the dry cleaning solvent from the articles in the basket. The solvent drains to the bottom of the chamber 1 and into the still since the dump valve remains open through the twenty-first time interval. There is a pause in the rotation of the basket during the twenty-first interval, and at the end of the twenty-first interval switch S5 moves to its neutral position to close the dump valve 95, and simultaneously the switch 86 moves to its neutral position to close the equalizer valve 107.

The drying and distillation cycle of the machine starts with the twenty-second time increment. Switch S2 closes on its top contact, which supplies current to a transformer T1 to energize the heater relay 41. This closes the heater relay contacts 43 to close the circuit to the heater 35. At the same time a machine cycle counter CTR connected across the secondary winding of the transformer is advanced. Simultaneously, switch S3 closes on its bottom contact again to operate motor 49 at its low speed to turn basket 3 at approximately 43 rpm. Switch S7 closes on its top contact again to start the vacuum pump 17 to evacuate chamber 1. The vacuum pump continues to operate through the forty-fourth time interval and maintains a vacuum in the chamber during the drying cycle. The vacuum in the chamber causes the evaporative dry cleaning fluid to boil and rapidly evaporate, thereby substantially reducing the overall drying cycle time. Operation of the heater 35 prevents the evaporative dry cleaning fluid from freezing in chamber 1 during the drying cycle as a result of rapid evaporation. Also at the beginning of the twenty-second time interval, switch S8 closes on its bottom contact again to energize the hot water solenoid 103 so that hot water is circulated through the coil 97 in still 9 to vaporize dry cleaning fluid and other liquids therein. The motor 47 is periodically switched from its low to high speed during the drying cycle as indicated in the FIG. 8 chart to prevent the work from adhering to the basket.

At the beginning of the thirty-sixth time interval, switch S10 opens to take the timer motor 201 out of the circuit. All ten switches 81-810 of the sequence timer switch 199 then remain in status quo until such time as the vacuum switch 127 closes to energize the timer motor 201 thereby to continue the sequential operation of the switches. Switch 127 is normally open and the timer motor is by passed until such time as the vacuum required to close switch 127 is reached in chamber 1. As long as the work is moist and emitting vaporized dry cleaning fluid in the chamber, the vacuum in the chamber does not increase suificiently to close switch 127. Only when the work is dried does the vacuum increase sufficiently to close switch 127. Thus, switch 127 is a dry sensor, and assures removal of articles from the dry cleaning machine at a uniform dryness. In the event switch 127 closes prior to the time that switch S10 opens, then the motor 201 continues to run without interruption and the machine continues its normal sequential operation. Operation of dry sensor switch 127 only prolongs the drying cycle of the machine until such time as the clothes have been dried. When the switch 127 energizes motor 201, and the thirty-seventh time interval is reached, switch S10 closes on its top contact and energizes the timer motor throughout the balance of the cycle.

At the end of the forty-second time interval, switch 82 opens to take relay 41 out of the circuit, thereby opening the circuit to the heater 35 to terminate heating in tub 3. At the beginning of the forty-third time interval switch S5 closes on its top contact to close the circuit to the vacuum break valve 111, which returns chamber 1 to atmospheric pressure. This valve remains open until the end of the dry cleaning cycle.

At the start of the forty-fourth time interval, switch S9 closes on its bottom contact, to open the air bypass valve '87 so that the gases being pumped by the vacuum pump 17 from chamber 1 are discharged to the atmosphere. The vacuum pump stops operating at the end of the forty-fourth time interval when switch S7 closes on its top contact to de-energize relay R2. During the final time interval of the cycle, switch S4 closes on its top contact, which operates the mechanism in the meter B to reset it and prepare the machine for the next cycle of operation.

Operation of the machine is as follows:

Work to be cleaned is loaded in basket 3, and door D V is closed, thereby closing switch DS to the solenoid-operated door lock DL and closing switch to the coin meter B while simultaneously opening the circuit to the blower 117 and valve 113. Coins are then inserted to energize stepper coil 184 via coin switch 189 to throw the homing and bypass switch 185 and power start switch 181 over from their FIG. 7 initial position. This closes the circuit to programmer P, and switch S3 starts the motor 49 to rotate basket 3 at tumble speed to tumble the work in the basket. Simultaneously, switch S7 closes to start the vacuum pump 17 which evacuates air or other gases from the chamber or tub 1. The gases are discharged 1 1 to the atmosphere through the valwe 87 which was opened by switch S9. Hot water is directed through the coil 97 in the still during the initial time interval. The timer motor is started by switch S10.

The vacuum pump operates for the first two time intervals, producing approximately 20 inches of vacuum in the chamber 1. The vacuum pump then stops and air bypass valve 87 closes. Switch S6 opens fill valve 63 to deliver about eleven gallons of dry cleaning solvent from section 57 of tank to chamber 1 during the third to the sixth time intervals of the cycle. Air from the accumulator tank 135 prevents vapor lock in the solvent tank. Delivery of the solvent tochamber 1 reduces the vacuum therein to about 7 inches of mercury. About two fluid ounces of detergent from tank 119 is supplied to chamber 1 during intervals six and seven of the wash cycle by operation of switch S8. Switch S7 opens the defrost valve at the third time interval and the refrigerated coils of condenser 13 are defrosted for nine increments of the cycle.

At the tenth interval, switch S6 opens the equalizer valve 107 and pressure between chamber 1 and still 9 is equalized. The dump valve 95 is open from the twelfth through the twenty-first intervals and used dry cleaning fluid is discharged from tub 3 into still 9. This further reduces the vacuum in the tub to about 5 inches of mercury. While the dump valve is open the basket 31 is turned at its tumble speed of 43 rpm, then at its distribution speed of 63 rpm, and finally at its extraction speed of 425 rpm. to extract as much as possible of the liquid solvent from the clothes, such being drained from chamber 1 into the still. The basket 31 pauses during the twentyfirst increment.

The dump and

equalizer valves

95 and 107 close at the end of the twenty-first inter-val and the vacuum pump again commences operation. Simultaneously hot water begins circulating through the still coils 97 for vaporizing fluids in the still. The motor 49 starts and turns basket 31 at speeds of 43 and 63 rpm, the tumbling and distribution speeds, respectively. Switch S2 starts the heater 37 to heat the clothes in basket 31 and boil off the dry cleaning fluid. As the pressure in chamber 1 is lowered by the vacuum pump, the boiling point of the liquid dry cleaning fluid is lowered and this, together with the heat supplied by heater 37, results in rapid evaporation of dry cleaning fluid in the chamber. As the dry cleaning fluid is vaporized, the vacuum in the chamber is increased from about 12 inches of mercury at time interval twenty-one to about 27 inches of mercury at interval thirty-five.

The timer motor 201 is taken out of the circuit by switch S10 during the thirty-sixth time interval so that the drying cycle continues until the vacuum increases to about 28 inches of mercury and switch 127 closes. When this occurs, the timer motor 201 starts and again controls the dry cleaning cycle. After the forty-second time interval, the clothes are dry and vacuum break valve 111 opens and air enters chamber 1. One time interval later the air bypass valve 87 opens and air is discharged from vacuum pump 17 to the atmosphere. After the forty-fourth time interval, switch S7 opens to stop the vacuum pump and end the dry cleaning cycle. The door D can then be opened and the work removed from the basket. Blower valve 113 opens and blower 117 starts when the door opens to assure removal of residual gases in the chamber 1.

At the beginning of the drying cycle (interval twentytwo) hot water begins circulating through still 9 and vaporizes the dry cleaning fluid. The pressure in the still from operation of vacuum pump 17 and evaporization in the still moves the vaporized fluid through the conduit 12.5 to the condenser .11. Cool water in condenser 11 condenses a large portion of the vaporized dry cleaning fluid which is then returned to section 57 of tank 5. A portion of the dry cleaning fluid in tank 5, including any water condensed in condenser 11, is transferred over partition 55 into section 59 and eventually removed from the storage tank.

The vapors remaining are transferred through line 133 to the accumulator tank 135 and ultimately to the refrigerated condenser 13. The refrigerated condenser 13 condenses even more of the vaporized dry cleaning fluid and transfers the condensate through the line to the collector 157. The remaining gas is primarily air and it is transferred through the line 159 into the refrigerated stripper 15 where substantially all of the remaining dry cleaning solvent is condensed and discharged into the collector 157. The remaining gases pass through the check valve 169 and the control orifice or valve 171 to the atmosphere. The dry cleaning fluid collected in collector 157 is transferred to still 9 during the twelfth to the twenty-first time intervals of the next cycle.

It is to be noted that vacuum is drawn in chamber or tub 1 throughout the cycle. This means that if there is any leakage as regards chamber or tub .1, it is leakage of air into the chamber rather than leakage of dry cleaning fluid out of the chamber, this air being passed through the recovery system and discharged to atmosphere from stripper 15. If chamber 1 were at atmospheric pressure or higher than atmospheric pressure during the cycle, any leakage (such as leakage through the shaft seal 34 as may occur) would result in loss of dry cleaning fluid. The latter is relatively expensive, and for economical operation it is important that loss of fluid be avoided, and that substantially all fluid used in the chamber 1 be recovered. The machine and method of this invention accomplish this. Use of the vacuum pump 17 greatly facilitates drying of the work and substantially reduces the time cycle. A dry cleaning machine of this invention using a Freon solvent can be operated on a cycle of about 12 to 16 minutes as compared to the usual 45 minutes for present dry cleaning machines using conventional dry cleaning solvents. This reduction in the cycle time affords a substantial economic advantage to the coin operated installation and to the professional dry cleaner.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in. the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A dry cleaning machine comprising a vacuum chamber for receiving work to be cleaned and then dried, means for effecting agitation of work in said chamber during a cleaning cycle and a subsequent drying cycle, a closedcircuit fluid system for said chamber comprising means for supplying a quantity of evaporative dry cleaning fluid to said chamber for cleaning of the work, discharging used fluid from the chamber upon the termination of a cleaning cycle, and reconditioning the fluid for reuse, and vacuum means in communication with the chamber for drawing a vacuum in said chamber for cleaning and drying of the work under vacuum in the chamber, said vacuum means being in communication with the chamber above the level of fluid therein, and said vacuum means comprising a vacuum pump having its inlet connected to the chamber and its outlet connected to the closed-circuit system for pressurizing the latter.

2. A dry cleaning machine as set forth in claim 1 wherein the fluid system comprises a storage tank for the fluid, means for receiving used fluid from the chamber and vaporizing the fluid, and means for condensing the vaporized fluid and delivering the condensate to the storage tank.

3. A dry cleaning machine as set forth in claim 2 wherein said vaporizing means comprises a still and means for circulating hot water through the still in heat-exchange relation to fluid in the still, and said condensing means comprises means for circulating a coolant in heat-exchange relation with vapor delivered from the still.

4. A dry cleaning machine as set forth in claim 3 wherein the vacuum pump has its outlet connected to the still for pressurizing the still.

5. A dry cleaning machine as set forth in claim 3 further comprising means for equalizing pressure between the chamber and the still for enabling discharge of fluid from the chamber to the still.

6. A dry cleaning machine as set forth in claim 5 further comprising means for breaking the vacuum in the chamber at the completion of the drying cycle.

7. A dry cleaning machine as set forth in claim 3 wherein said condensing means comprises first condensers, a primary condenser for receiving vapors from the still and delivering the resultant condensate to the storage tank and auxiliary condensing means for condensing vapor entrained in air delivered from the storage tank and delivering the resultant condensate to a collector, and means for returning condensate from said collector to the still.

8. A dry cleaning machine as set forth in claim 7 wherein said auxiliary condensing means has an air outlet in restricted communication with the atmosphere.

9. A dry cleaning machine as set forth in claim 7 wherein the primary condenser is water-cooled, and said auxiliary condensing means comprises a refrigerant-cooled condenser converted to said collector, and a refrigerant-cooled stripper also connected to said collector and having an air outlet in restricted communication with the atmosphere.

It A dry cleaning machine as set forth in claim 8 having a vapor accumulator in communication with said storage tank and said auxiliary condensing means.

11. A dry cleaning machine comprising a vacuum chamber; a door for said chamber; a rotary basket in said chamber adapted for reception of work to be cleaned and dried and unloading of finished work via said door; a closed-circuit fluid system for said chamber comprising a storage tank for dry cleaning fluid, means for delivering a quantit or" fluid from the storage tank to the chamber for a cleaning cycle, a still connected to said chamber for receiving used fluid from the chamber after a cleaning cycle and vaporizing the fluid, and means for condensing vaporized fluid from the still and returning the resultant condensate to the storage tank, a vacuum pump having its inlet connected to the chamber and its outlet connected to the still, said pump being adapted to draw a vacuum in the chamber for cleaning and drying of work under vacuum in the chamber and to pressurize the still for pressurized discharge of vapor from the still, and means for programming a cycle of the machine comprising operation of the pump to draw a vacuum in the chamber, delivery of fluid from the storage tank to the chamber, rotation of the basket for cleaning the work under vacuum in the chamber, followed by discharge of fluid from the chamber to the still, and rotation of the basket for drying the work under vacuum in the chamber.

12. A dry cleaning machine as set forth in claim 11 wherein said programming means includes a timer, and said machine includes means for sensing dryness of work being dried in the chamber and controlling said timer to control the length of the drying cycle of the machine.

13. A dry cleaning machine as set forth in claim 12 wherein said sensing means comprises a switch responsive to the degree of vacuum in the chamber and controlling the timer.

14. A dry cleaning machine as set forth in claim 11 wherein said storage tank is a closed tank, wherein said condensing means comprises a primary condenser in said fluid system between the still and the tank, and auxiliary condenser means in said fluid system for condensing vapors discharged from said storage tank, an accumulator connected into said system between said storage tank and said secondary condenser means, a collector for collecting condensate from said auxiliary condensor means, and means for delivering condensate from said collector to the still.

15. A dry cleaning machine comprising a vacuum chamber; a door for said chamber; a rotary basket in said chamber adapted for reception of work to be cleaned and dried and unloading of finished work via said door, a closed-circuit fluid system for said chamber comprising a storage tank for dry cleaning fluid, a fluid connection between said tank and chamber having a fill valve therein, a still, a fluid connection between said chamber and the still having a dump valve therein, and means for condensing vaporized fluid from the still and returning the resultant condensate to the tank, a vacuum pump having its inlet connected to the chamber and its outlet connected to the still, said pump being adapted to draw a vacuum in the chamber for cleaning and drying of work under vacuum in the chamber and to pressurize the still for pressurized discharge of vapor from the still, means including an equalizer valve for equalizing pressure in the chamber and the still, means including a vent valve for venting the tank to atmosphere, means for programming a cleaning cycle of the machine followed by a drying cycle with the cleaning cycle comprising operation of the pump to draw a vacuum in the chamber, rotation of the basket, opening of the fill valve for delivery of fluid from the storage tank to the chamber for cleaning of the Work by said fluid, followed by opening of said equalizer valve for equalizing pressure in the chamber and still, opening of the dump valve for draining used fluid from the chamber into the still, closure of the equalizer valve and the dump valve, drying of the work under vacuum in the chamber, and opening of the vent valve: for venting the chamber to atmosphere.

16. A dry cleaning machine as set forth in claim 15 wherein said programming means includes means for starting said pump at the start of a cleaning cycle, stopping it during the filling of the chamber and the remainder of the cleaning cycle, restarting it for the drying cycle, and stopping it toward the end of the drying cycle.

17. A dry cleaning machine as set forth in claim 16 wherein said programming means includes a timer motor, and means for stopping said timer motor at a predetermined point in the drying cycle, and wherein there is provided means for sensing dryness of work in the chamber and restarting said timer motor in response to said sensing mean for controlling the length of said drying cycle.

18. A dry cleaning machine as set forth in claim 17 wherein said sensing means comprises a switch responsive to the degree of vacuum in the chamber and acting to restart the timer motor when the pump has drawn a predetermined degree of vacuum in the chamber corresponding to a predetermined dryness factor of the work.

References Cited UNITED STATES PATENTS 2,126,426 8/1938 Traube 6820 X 3,222,896 12/1965 Schneider 68-48 X 1,776,190 9/1930 Mishaw 68-20 1,865,218 6/1932 Spalding 68-18 1,985,376 12/ 1934 Lindenberger 8-142 3,238,750 3/1966 Candor et al 68--20 WILLIAM I. PRICE, Primary Examiner.

US. Cl. X.R. 68-18