US3012332A - Heat storage reservoir for clothes dryer - Google Patents

Description

Dec. 12, 1961 J. w. TOMA 3,012,332

HEAT STORAGE RESERVOIR FOR CLOTHES DRYER Filed April 16, 1959 4 Sheets-Sheet l F'lCil INVENTOR J'OHN W. TOMA WWW H IS ATTORNEY Dec. 12, 1961 J. w. TOMA 3,012,332

HEAT STORAGE RESERVOIR FOR CLOTHES DRYER Filed April 16, 1959 4 Sheets-Sheet 2 FIG. 2 3 35 Ll: F P n 15 was -"l \49 7 |Z.\ i

l I I u L l I 72. I 58 I "1 67 x e a2 84 I L I F'IGA- as I m I I M a INVENTOR L;: 1 r JOHN W. TOMA j F163 78 BY MM H 15 ATTORNEY Dec. 12, 1961 J. w. TOMA 3,012,332

HEAT STORAGE RESERVOIR FOR CLOTHES DRYER Filed April 16, 1959 4 Sheets-Sheet 3 FIGS no INVENTOR.

:roo-m w TOMA HIS ATTORNEY J. w. TOMA 3,012,332

HEAT STORAGE RESERVOIR FOR CLOTHES DRYER 4 Sheets-Sheet 4 F' l G. 6

H\S ATTORNEY Dec. 12, 1961 Filed April 16, 1959 United States Patent 3,012,332 HEAT STORAGE RESERVOIR FOR CLOTHES DRYER John W. Toma, Louisviile, Ky., assignor to General Electric Company, a corporation of New York Filed Apr. 16, 1959, Ser. No. 806,933 3 Claims. (Cl. 34-45) This invention relates to automatic clothes dryers, and more particularly to electric clothes dryers for domestic use.

Clothes drying machines of the type provided for domestic use usually include some arrangement for heating the clothes so as to evaporate liquid from them. Conventionally, the vapor so produced is carried off by a current of air. The transformation of the liquid into vapor requires a substantial amount of energy input, and this energy input is provided in electric dryers by the heating coils, i.e., the resistance heater energized from the domestic source of power. It will readily be apparent that the more energy in the form of heat that can be provided to the clothes by the electric heater, within safe limits, the faster will be the rate of evaporation and the quicker the clothes will become dry.

Since, as is well known, the power varies with the square of the voltage for any given resistance, it follows that a doubling of the voltage across the heating resistance results in a quadrupling of the power input. As a result, many domestic dryers are formed to be operated on 220 volts alternating current rather than the 110 volts which for many years has been commonly provided in most electrically powered buildings, particularly homes. The provision of 220 volts requires special connections and special wiring; while such connections and wiring are often built into homes presently being erected, there are millions of homes as to which the provision of 220 volts as a source of power may be a matter of some expense. Because of this, it is highly desirable that, in

' parallel with the production of 220 volt dryers which are provided for use in those homes which are properly wired for the reception of such appliances, a suitable clothes drying machine for operation on 110 volts be provided. While such machines are presenty provided, and operate in a highly satisfactory manner, they have the inevitable disadvantage with respect to machines operated on 220 volts that, because of the lower power input, a substantially longer period of time is required to dry any given clothes load.

Because of the foregoing, it is an object of this invention to provide a dryer having the ability to store energy during periods of non-use and to release this energy during periods of use at the same time that energy is received from the domestic source of power.

More specifically, it is an object of this invention to effect energy storage by suitable means connected to the domestic source of power when the machine is not connected to the source of power for drying purposes.

It is a further object of the invention to provide an improved clothes dryer having energy storing means wherein the energy storing means are alternatively operable with the main electric drying means energized during selective drying cycles, and wherein auxiliary heating means is operated by the stored energy substantially concurrently with the energization of the main electric heating means.

In carrying out my invention in one form thereof, I provide a clothes drying machine with a clothes container and with main electric heating means which are energizable by connection to an external source of power to heat the clothes in the container and thereby evaporate moisture from them. In addition, the machine includes 3,012,332 Patented Dec. 12, 1961 means operable by connection to the source of power to store energy, and auxiliary heating means operated by the energy stored which is also positioned to heat the clothes in the container. The main electric heating means and the auxiliary heating means are caused to operate substantially concurrently by suitable control means which also connects the energy storing means to the source of power alternatively with energization of the main electric heating means. By this arrangement, substantially more energy in the form of heat may be provided during a drying cycle than is feasible if only the energy from the source of power is used. By storing power during non-use of the machine and releasing the stored power during drying cycles, substantially more energy is provided for drying the clothes and drying of the clothes is thus achieved substantially faster than otherwise possible.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. My invention, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings.

In the drawings,

FIGURE 1 is a side elevational view of a clothes dryer incorporating my improved drying arrangement, the view being partially broken away and partially sectionalized to illustrate details;

FIGURE 2 is a horizontal sectional view of the dryer with the drum removed and with certain surfaces broken away and partially sectionalized to illustrate further details;

FIGURE 3 is a schematic diagram showing in simplified form a circuit appropriate for use in my improved drying machine;

FIGURE 4 is a cam chart illustrating the sequence of operation of the switches shown in FIGURE 3;

FIGURE 5 is a side elevational view of a clothes dryer incorporating a second embodiment of my invention, the view being partially broken away and partially sectionalized to illustrate details;

FIGURE 6 is a horizontal sectional view of the dryer of FIGURE 5, partially sectionalized and with certain surfaces broken away to illustrate further details;

FIGURE 7 is a schematic diagram showing a simplified circuit for use in the embodiment of my invention illustrated in FIGURES 5 and 6; and

FIGURE 8 is a cam chart illustrating the sequence of operation of the switches shown in FIGURE 7.

Referring now to FIGURES l and 2 of the drawings, I have shown therein a domestic clothes dryer 1. Dryer 1 includes a clothes tumbling receptacle or drum 2 pro- .vided within a suitable outer casing or cabinet 3 which completely encloses it on all sides. The drum is mounted for rotation within cabinet 3 on a substantially horizontal axis, and is generally cylindrical in shape, having a first central outer wall portion 4, second and third outer wall portions 5 and 6 located respectively adjacent the ends of the drum, a back wall 7, and a front wall 8. Outer wall sections 4, 5, and 6 are imperforate over their entire length, so that the entire outer shell of the drum is imperforate; on the interior surface of central portion 4 there is provided a plurality of clothes tumbling ribs 9.

The front of drum 2 is rotatably supported within the outer casing 3 by an idler roller wheel 10 and a driving roller wheel 11 (FIGURE 2). The idler wheel 10 is rotatably secured to the top of an upwardly extending member 12 which is secured at its bottom to the base 13 of the machine (FIGURE 1). Driving roller 11 is mounted on a shaft 14 supported by a bearing 15 mounti ed on portion 15a of base 13; the shaft is secured to a 3 pulley 16 which is driven from a belt 17; belt 17 in turn is powered by a pulley 18 mounted on shaft 19 of an electric motor 20. Themotor, pulleys, and roller 11 are so proportioned to drum 2 and each other that the drum is rotated by roller 11 at an appropriate speed clothing placed 23 by suitable electrical insulators 51, Thus, to enter basket 2, the air which has entered the casing through opening 32 has to pass first over the coiled pipe section 33 and then over the electrical heating element 50, be-

extension 26 of the basket rear wall 7. With this arrangement, the rear of basket 2 is rotatably supported and with a plurality of perforations 28 extending in an annulus around its back wall 7. By means of spaced bracket members 29 and3t} the combination support and baffle member 23 and cabinet wall 21 support a second bathe member 31. The two baffle members cooperate to forman air path from a suitable air inlet into the cabinet, such as inlet 32, to the perforations 28 in rear wall 7 of the basket. In addition to providing a support for baffle member31, brackets 2Q and 30 also cooperate with the rear wall 21 of the casing and with bafile member 31 to support a number of coils of piping 33; pipe section 33 is preferably provided at frequent intervals along its length with suitable heat conductive fins 34 so that a large heat transfer area is provided to transfer heat from the interior of the pipe section 33 to air passing over the pipe.

Any suitable hot liquid, preferably water, is circulated through pipe 33 from a reservoir 35 when it isdesired to heat air passing over the pipes. The pumping of the liquid from the reservoir 35 through the pipe is readily achieved by means of any suitable pump such as that generally indicated by the numeral 36. Pump 36 consists of a length of flexible material 37 having an inlet valve 38, an outlet valve 39, and a squeezing assembly 40. The squeezing assembly, as best seen by reference to FIGURE 1, consists of astationary member 41. and a m mber 42 pivotable about a pin 43 in response to movements of an actuating lever 44. At its other end lever 44 is secured to an eccentric 45 which rotates with shaft 25 and consequently the basket 2. It will readily be seen that once each rotation of the basket the eccentric connection of lever 44- to shaft 25 will cause the lever to raise member 42 and squeeze the resilient tubular portion 37 of the pump, andonce each revolution the lever 44- will descend and release the pressure on the resilient portion 37.

Valve 38 is so formed that a decreased pressure in the part 46 of the pump between the two valves causes it to open, While valve 39 is so formed that an increased pressure within part 460i the pump causes is to open. As a result, each time the pump portion 46 is squeezed by assembly valve 39 will open and the squeezing action will force a supply of liquid up through pipe 47 to the coiled pipe section 33. Each time assembly 40 releases part '46 of the pump, additional liquid will be sucked up from reservoir 35 through pipe 48. It will thus be seen that once for each revolution of basket 2 liquid will be sucked up into the pump and then delivered by the pump into the coiled pipe 33. After the liquid traverses the full length of thecoiled pipe section 33, it is returned to the reservoir 35 through a suitable pipe section 49.

' In addition to the coiled pipe section 33, a suitable electric heating element St! is secured to b fil member basket.

tween the bafiles 23 and 31, and then through perforations 28 into the basket 2. To prevent leakage of this heated air back into the cabinet instead of into the drum, a suitable seal may be provided between the stationary ba'flie 31 and the adjacent rear wall 7 of the For instance, as shown, a circular felt strip or ring seal 52 may be secured to the baffle 31 and arranged to provide a sliding seal with rear wall 7 of the basket.

The front opening 27 v of the basket is substantially closed by means of a stationary bulkhead generally indicated at 53. Bulkhead 53 is made up of a number of adjacent members including the inner surface 54 of an access door 55 mounted on the dryer cabinet, a stationary frame 56 for the door, the inner surface 57 of an exhaust duct 58 leading from the drum, and an annular flange 59 mounted on the frame 56 and on the duct wall. It will be noted that a suitable clearance is provided between the inner edge of the drum opening 27 and the edge or" bulkhead 53; any substantial air leakage through theopening 27 between the interior and the exterior of the basket is prevented by a second'suitable ring seal 6%, preferably formed of felt-like material in the same mannor as ring seal 52, secured to flange 59 in sealingrela" tionship with the exterior surface of basketwall 8.

Front opening 27, in addition to serving as part of the air flow path through-the basket, also serves as a means whereby clothes may be loadedinto and unloaded from the drum. The door 55, whose inner surface forms part of the bulkhead closing the opening, is mounted on cabinet 3 and when the door is opened the clothes may be inserted into or removed from the drum through the door frame 56. It will be noted that the door includes an outer imperforate section 61 and an inwardly extending hollow section 62rnounted on the outer fiat section. The hollow section extends into the door frame 56 when the door is closed, and the door surface 54 which comprises part of the combination bulkhead 53 is actually the inner'wall of this hollow section.

The air outlet from the basket is provided by a perforated opening 63 formed in the inner Wall 54 of hollow door section 62. The bottom wall of the hollow door section 62 and the adjacent wall of door frame 56 are provided with aligned openings 64 and 65, with opening 65 providing the entrance to duct 5%. As shown, a lint trap 66, which may comprise a fine mesh bag, is preferably positioned in exhaust duct 58 at opening 65, the bag being supported by the door frame 56.

gDuct 58 leads to suitable air moving means which may, as shown, comprise a centrifugal blower 67 secured to rotate with a pulley 68 which is driven by a belt 69 in turn rotated by a pulley secured to theend of motor shaft 19. The outlet of blower 67 communicates with an outlet duct 71 which extends to an opening 72 in the back 21 of the cabinet 3. During operation of motor 20, the rotation of blower 67 causes air to be drawn into cabinet 3 through opening 32, over the coiled pipe 33 and the heating element 50, through perforations 28 into drum 2, across the drum, through perforated opening 63 and aligned openings 64 and 65 into duct 58, and then through the blower 67, 'the outlet duct 71, and opening 72 to atmosphere.

Referring now to FIGURE 3, a suitable control arrangement 72a including a timer motor 73 is provided.

" The timer motor drives a plurality of can! members whose rises and dwells are shown schematically in FIG- .78 to any desired position so that upon suitable positioning of the cams by member 78 timer motor 73 will cause a complete drying sequence to take place. Conventionally manual control member 78 is positioned on a backsplasher member 79 secured to and located above the casing 3 of the machine, with the control 72a mounted within the housing as shown.

A pair of electric conductors 80 and 81 are provided to connect the electrical components of the machine 1 to a suitable source of power, generally the 115 volt 60 cycle alternating current power provided in virtually all locations in the United States. The timer motor 73 is connected across the source of power in series with timer switch 74 so that when switch 74 is open the timer motor is inoperative. Also connected across the source is the main electric heating coil 50, which is positioned in series with timer operated switch 75. In similar fashion, the drive motor 28 is connected across the source in series with timer operated switch 76. The fourth timer operated switch 77 is connected in series with an electrically insulated heating unit 82 which, as shown in FIGURE 1, is secured to reservoir 35 so as to extend therewithin in heating relation to the liquid contained within the reservoir. In addition to being controlled by the operation of switch 77, the energization of the electric heater 82 is controlled by the closing of a switch 83 responsive to a thermostatically sensitive bulb 8'4, with switch 83 opening when bulb 84 senses a predetermined high temperature. The bulb 84 may be located at any appropriate point within or adjacent the reservoir 35 so as to sense the temperature of the liquid in the reservoir.

Reference to FIGURE 4 shows a typical cam arrangement whereby, when the dial 78 is rotated to a predetermined position, switches 74, 75 and '76 are closed to cause the conventional operation of the drying machine. The energization of the timer motor 73 causes the timer motor to drive the cams, with the drive continuing until the oif point is reached at which time switches 74, 75 and 76 open to end the heating cycle. During the operation of the timer motor it will be observed that switch 75 is also closed to complete an energizing circuit to heater 50 thereby causing the heater to be energized. conventionally, a suitable thermostat such as that shown at 85 is provided in series with heater 50 to limit temperatures within the machine 1 to a safe range. At the same time that the timer motor 73 and heater 50 are energized, drive motor 20 is energized. This causes rotation of the basket at an appropriate speed to tumble clothes in the basket, rotation of blower 67 to move air over the coiled pipe section 33, the heater 5!), and through the basket, and also causes operation of pump 36 as described to cause hot liquid from reservoir 35 to be pumped through coiled pipe section 33 and down again to the reservoir.

It will be observed that the switch 77, which has a closed position when timer motor 73 is not timing a cycle, is provided with an 'open position during the drying sequence, that is, during the energization of heater 50. It will readily be seen that during a drying cycle only the heater 50 of the two electric heaters will be energized so that the full amount of power available (except for the relatively small amount used by motor 20 and motor 73) is available for heater 50. At the same time, the fact that the liquid within reservoir 35 has been heated by heating coil 82 causes a substantial amount of heat to be transferred through fins 34 to the air from the liquid as it is circulated through the coiled pipe section 33. In this manner, after the air enters through opening 32 and circulates over the coiled pipe section, it is preheated by the time it reaches electric coil 50. This has the result that, with the preheating of the air as provided by the coiled pipe section 33, the air reaches a much higher temperature after it has passed over heating coil 58 than is the case where the air is merely at room temperature at the time it passes over the electric coil. In this manner, the energy stored in the heated liquid within reservoir 35 is given up during a drying sequence to assist in providing faster drying of the clothes in drum 2.

It will be further observed from FIGURE 4 that when the off position is reached at the end of the drying sequence, and switches 74, and 76 are open, switch 77 is then closed to cause energization of coil 82. Since the timer motor 73 is no longer operating, the switch 77 remains closed and the coil 82 remains energized except as controlled by thermostat switch 83. This action maintains the liquid in the reservoir at a high temperature in readiness to assist in minimizing the time required for a subsequent drying sequence.

It will further be seen that, while a portion of the cam surface controlling switch 77 causes switch 77 to be closed during the time the other switches are open, there is a portion of it which opens switch 77 at the same time the other switches are open. Thus, in cases such as the situation where a dryer is not to be used for a period of several weeks, the control 78 may be set so that the heater 82 will be de-energized at the same time as the other electrical components in the machine. Otherwise, as shown, the heater 82 will maintain the liquid in reservoir 35 in a state of readiness to assist in decreasing the time required for a heat drying operation.

It will thus be observed that the construction provides a system for storing energy in machine 1 when the machine is not being used for drying clothes. In the particular embodiment described, the energy is stored by means of a liquid which is heated by a coil energized from the same source as used for the energization of the electric heater during a drying operation. While any suitable liquid may be used, it will be recognized that the most inexpensive liquid with very good heat transfer characteristics is water. It will further be observed that the storing of the energy is alternative to the energization of the other electrical components, particularly the main electric heater 50.

In order to retain complete clarity in the explanation of the invention, a very simple drying cycle with con tinuous and concurrent energization of the timer motor 73 and of the electric heater 5! has been described. However, it will readily be understood that the invention may be used in the type of cycle where the electric heater 50 and timer motor 73 (or either one) are cycled on and off by appropriate timing, thermostatic, or humidityresponsive controls during the operation of the machine. It is further conceivable that in such a case the cam controlling switch 77 might be so formed as to cause energization of heating coil 82 during a drying cycle, that is, during the operation of several of the other components of the machine, provided it is not carried on at the same time as the energization of the main heating coil 50. In other words, it is important that the energization from the source of electric power of heating elements 50 and 82 be of an alternative nature, with each one being off as the other one is connected.

Referring now to FIGURES 5 to 8, a second embodiment of the invention will be described with the same numerals being used for like parts. It will be readily observed that the drive for the machine of FIGURES 5 and 6 is substantially the same as that of the machine of FIGURES 1 and 2. The only minor difference is that because there is no large reservoir 35 taking up the entire lower portion of the machine, the machine of FIGURE 5 has the motor 20 positioned beneath drum 2 and somewhat to the rear thereof, as is more conventionally provided. This permits the drive roller 11 to be positioned at the rear of the drum in driving relation to portion 5 of the wall thereof, and two idler rollers 10 are pro vided at the front of the machine so that between the two idler rollers 10 and the drive roller 11 the drum is supported. With this arrangement, the stub shaft 25 projecting from part 26 secured to rear wall 7 of the drum effects a guiding function in its relationship with support and baflie member 23 rather than a supporting V 7 function as provided in the machine of FIGURES 1 and 2.

The only other change in the location of parts occurs with relationship to the blower-which, because of the position of the motor in the embodiment of FIGURES and 6, is driven directly thereby instead of through a belt and pulley arrangement, It will be observed that, just-as before, once the air has entered drum 2 through perforations 28, it passes through the drum, and then through perforated opening 63 in hollow door section 62, openings 64 and 65, lint trap 66, duct 58, blower 67, outlet duct 71, and opening 72 to atmosphere.

Also as before, the air to be used for drying purposes enters casing 3 through inlet 32. However, the construction-of the baffles in the heating arrangement through which the air passes prior to entry into drum 2 is somewhat different from that of the embodiment of FIGURE 1, and will now be described. The baffie 23 in FIGURE 5 is the same as that of FIGURE 1, in that it is welded to the rear wall 21 of casing 3, and has an opening 24 therein which provides the necessary guidance for shaft 25 of drum 2. Battle 23 is in spaced relation to a second bafile member 101 which is rigidly secured to the rear wall 7 of basketl and is provided with openings 102 therein. With this construction, the air pulled in through opening 32 enters the space 103 between bafiles 23 and 101, passes over a pair of heating elements 104 and 105, and through openings 102 and perforations 28 into the drum 2. The electric heating elements 104 and'105 are preferably supported, as shown, from the battle member 23 by means of electrical insulators 106 and 107 respectively.

Referring now to FIGURES 7 and 8 it will be seen that,

' as before, the electrical components of the machine are energized from a two wire power supply through conductors 80 and 81, and that timer motor- 73, drive motor 20, and the main heater 105 (equivalent to heater 50 in the embodiment of FIGURES l and 2) are connected across the line in series with switches 74, 76 and '75 respectively. In addition to switches 74, 75 and 76, whose function has been explained in connection with the embodiment of FIGURES 1 and 2, timer motor 73 in the second embodiment controls a pair of switches 108 and :109. As shown in FIGURE 8, switch 108 is preferably closed alternatively to the other switches and particularly to switch 75 which controls energization of heater 105. Switch 109, on the other hand, is closed substantially concurrently with the other switches.

Switch 108 is in series relation with an electric storage battery 110 which may, as shown in FIGURES 5 and 6, be physically located along one bottom side of the dryer within the casing 3. The storage battery is connected across the source of power through a battery charger 111" of standard construction. The battery charger may, as shown in FIGURES, be positioned on the same side of the machine as the battery but adjacent the top thereof as shown. With these connections, it will be clear that when switch 108 is closed a charging of battery 110, that is, the storing of energy therewithin, is effected through the battery charger device 111, the charger acting to control the input of energy so that when the battery is fully charged the charging effect ceases.

- Switch 109 controls the energization of auxiliary electric heater 104 which is, as shown, connected across battery 110 so that when switch 109 is closed and switch 108 is arrangement has been shown for effecting a drying operation, the system is completely compatible with the use of more sophisticated drying systems which are dependent on other factors such as temperature and humidity; The importanfpoint ofthe broader aspect of the invention is'that the storing of the energy be effected alternatively effected substantially concurrently with the energization of the main heater. Thus, for instance, it is readily conceivable that a suitable system could be set up to utilize the heat of fusion of a material. In other words, energy storage would be effected by melting the material during non-use of the dryer, and use of the energy would be achievedby letting the material cool back to its solid state.

While in accordance with'the patent statutes I have shown what at present are considered to be the preferred embodiments of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invenion, and I therefore aim to cover in the appended claims all such equivalent variations as fall within the true spirit and A ceptacle, main electric heating means energizable by connection to an external source of power and positioned to heat clothes in said receptacle, a liquid reservoir, electric means in said reservoir operable by connection to the source of power for heatingliquid in said reservoir, a heat transfer pipe section forming a closed liquid circuit with said reservoir and positioned to heat clothes in said receptacle when hot liquid is circulated therethrough, means for circulating liquid therethrough, control means providing substantially concurrent energization of said main electric heating means and circulation of said liquid through said heat transfer pipe section, said control means connecting said electric liquid heating means to the source of power for energization alternatively with energization of said main electric heating means.

2. The apparatus defined in claim 1 wherein air circulating means are positioned to circulate air first over said main electric heating means and said pipe section and then through said receptacle whereby the air is used as a medium for transferring heat to the clothes.

3. The apparatus defined in claim 1 wherein the liquid used is water.

References Cited in the file of this patent MacCracken et al Aug. 23, 1960

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