US3069785A

US3069785A - Clothes dryer with lint burner

Info

Publication number: US3069785A
Application number: US818160A
Authority: US
Inventors: Laurence J Mitter; Ronal H Whyte
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1959-06-04
Filing date: 1959-06-04
Publication date: 1962-12-25
Anticipated expiration: 1979-12-25

Description

Dec. 25, 1962 L. J. MITTER ETAL 3,069,785

CLOTHES DRYER WITH LINT BURNER Filed June 4, 1959 5 Sheets-Sheet 1 S'wlTcu CYcLE CHART I70 :72 I I74 176 1962 L. J. MITTER ETAL 3,069,785

CLOTHES DRYER wmz LINT BURNER Filed June 4, 1959 5 Sheets-Sheet 2 INVENTORS Rona) H. Mfg/fa 1 Z [aura/me Ll. )77if1er Dec. 25, 1962 L. J. MITTER ETAL CLOTHES DRYER WITH LINT BURNER 5 Sheets-Sheet 3 Filed June 4, 1.959

Dec. 25, 1962 L. J. MITTER ETAL CLOTHES DRYER WITH LINT BURNER 5 Sheets-Sheet 4 Filed June 4, 1959 Rona) 6 4. 8 in? O w T imfi, MM. A y? He w L. J- MITTER ETAL CLOTHES DRYER WITH LINT BURNER Dec. 25, 1962 5 Sheets-Sheet 5 Filed June 4, 1959 via 35% R I. 0

m A 7m w z. 2 nr 00 a y United States Patent 3,069,785 CLOTHES DRYER WITH LINT BURNER Laurence J. Mitter and Ronal H. Whyte, Dayton, Ohio, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed June 4, 1959, Ser. No. 818,160 13 Claims. (CI. 34-53) This invention relates to a domestic appliance and more particularly to an improved clothes dryer.

The operation of a clothes dry-ing apparatus wherein the clothes are tumbled in a heated air stream is accompanied by the evolution of lint or foreign matter from the clothes being tumbled. This lint must be disposed of if the heated air stream is to be circulated efficiently. In the prior art there are many methods of filtering lint from the circulating air stream. However, the prior art is directed to filters which must be removed periodically for cleaning. Where the operator fails to clean a clogged filter, the dryer air flow is reduced and the system efiiciency suitors. It is here proposed to eliminate the requirement for periodic filter cleaning and to disposed of lint by a lint burning system-a system which will not extend the total drying time and which will overcome the need for periodic filter checks.

Accordingly, it is an object of this invention to eliminate lint from a clothes dryer by a burning process which does not extend a normal drying cycle.

Another object of this invention is to initiate a lint burning cycle at the beginning of a clothes drying cycle.

It is also an object of this invention to mount a lint collector and burner on the door of a clothes dryer, whereby ash will be prevented from accumulating on the lint collector and whereby a large collecting and burning area may be disposed in the dryer air stream.

It is a further object of this invention to burn the lint while clothes in the dryer are still in a damp condition.

Another object of this invention is embodied in the provision whereby an electrically actuatable lint burner is mounted on a door of a clothes dryer and conditioned for energization only when said door is closed.

A still further object of this invention is to provide a lint collector and burner with means for eliminating the smoke and odor evolved during a lint burning process.

A more specific object of this invention is to provide a combination lint collector and burner which may be removably inserted in a dryer door and conditioned for energization by the insertion of said lint collector and burner in said door.

It is also an object of this invention to provide a clothes dryer door with a housing in the dryer air stream which is adapted to interchangeably receive either a lint filter or a lint collector and buner.

A still further object of this invention is the provision of means to reduce air flow in a clothes dryer at the beginning of a clothes drying cycle to facilitate the burning of lint and the rapid preheat of said clothes dryer.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a fragmentary perspective view of a clothes dryer front with an access door in open position.

FIGURE 2 is a sectional view taken along line 2-2 in FIGURE 3 showing a clothes dryer suitable for use with teachings of this invention.

FIGURE 3 is an elevational view with parts broken "ice away of a clothes dryer adapted for use with this invention.

FIGURE 4 is a sectional view taken along line 4-4 in FIGURE 3 showing the door mounted lint collecting and burning arrangement of this invention.

FIGURE 5 is an elevational rear view of the clothes dryer door with parts broken away and exploded to show the lint collector and burner in relation to the door.

FIGURE 6 is a schematic wiring diagram which is effective to control a lint burning cycle in accordance with the teachings of this invention.

FIGURE 7 is a cycle chart of the timer switches.

In accordance with this invention and with reference to FIGURE 1, a clothes dryer I0 is shown with a cabinet having a front wall 12 in which an opening 14 is provided. The recessed opening 14 terminates .in a shoulder or inset wall 16 which circumscribes an access opening or port 17 to a tumbling drum 58 therebehind. Adapted to close the opening 14 is a vertically pivoted door 20 having a lint collecting housing 22 mounted thereon and adapted to extend into said opening 17 when the door 20 is in closed position.

The lint collecting housing 22 is adapted to project into intercepting air flow relationship with air moving outwardly through opening 17 on its way to a series of front air duct or conduit openings 24 in a front port plate or collar 26. The lint collecting housing 22 is formed with a vertical inlet panel 28 in which a plurality of inlet ports Bil are formed. The inlet or rear housing panel 28 is joined to an inner panel 32 of the door 20 by a generally cylindrical housing wall 34. In the cylindrical portion 34 of the housing 22 a top insert opening 36 is cut out for receiving interchangeably either a lint collector or filter 33 (FIGURE 2) or a lint collector and burner 40 (FIGURES l and 4). A handle such as 41 on the burner 40 may be used for easily inserting or removing the filter 38 or the burner 49 from the housing 22. Since air must flow through the housing 22 on its way from the drum opening 17 to the port plate openings 24, the cylindrical wall 34 is provided further with a second or exhaust opening 42 in a bottom portion thereof to permit air to leave the housing 22.

One aspect of this invention is directed to the burning of lint wherein the collector 40 includes a heater or resistance element (described hereinafter) which may be selectively energized at the beginning of a clothes drying cycle. It is undesirable to have a source of heat or electrical energy unprotected and exposed to one operating the clothes dryer. For this reason, the lint collector and burner 40 may be conditioned for energization through a male plug 44- electrically connected through the door 20 and the housing '22 with the burn unit 40. When the door 24 is closed, the male plug 44 moves into cooperative relationship with a female plug 46 on the shoulder 16 in the recessed door opening 14. In this way, the lint burning element may be energized only when the clothes dryer door 20 is closed. Of course the selective control of the lint burning is a function of the timer as will be described more fully hereinafter.

To more clearly understand the structure of a clothes dryer suitable for use with this invention, reference may now be had to FIGURES 2 and 3. The clothes dryer 10, in addition to its front wall 12, door 20 and lint collector housing 22, includes a top cabinet portion 48, a rear wall '50, and

sidewalls

52 and 54. Extending generally parallel to the rear wall 5% is an interior bulkhead 56 for mounting a tumbling drum 58. The tumbling drum 58 is generally cylindrical in for-m and includes a rear Wall 60 which is perforated at 61 to permit ingress of air through the wall. A shaft 62 is afiixed to the wall 60 and is journaled in a spherical bearing 64 carried by the partition or bulkhead 56. Opposite the rear wall 60 in the drum is an annular front wall 66 which terminates in a generally cylindrical neck or collar portion 68 in axial alignment with the opening 17 formed by the collar orflange 13 of the port plate 26. It may be seen in FIGURE 2 that the port plate '26 has a radially outwardly directed flange 70 which is carried in a seal 72 and fixed thereby relative to the shoulder 16 of the cabinet opening 14. Thus, the inlet neck or collar 68 of the tumbling drum 53 circumscribes the drum support collar or flange 18 of the port plate 26 and is supported by and spaced therefrom by any suitable feltlike material 74. The feltlike material, of course, is primarily for sealing relationship of the air flow about the

rotary joint

18, 68 at outlet of the tumbling drum. To resist the downward thrust of the tumbling drum collar 63, several nylon blocks 76 or other suitable bearing material are interposed between the drum collar 68 and the port plate flange 18. In this way the tumbling drum 58 is supported for rotation and journaled at its rear Wall in the partition 56 and at its front end by the collar 18 of the port plate 26. The port plate 26 may be fastened to the front wall 12 of the dryer by any suitable fastening means such as bolt 77 through the port plate flange 70 on the cabinet shoulder 16. In order to improve the agitation of clothes within the tumbling drum during rotation thereof, baflles such as 78 may be included.

The air flow through the clothes dryer 10 is motivated by a blower 80 which is driven by a motor or other suitable prime mover 82 which serves also to rotate the tumbling drum 53 through a belt and pulley arrangement 84. Since the clothes dryer 1!) is of the vented type, the rear wall St is provided with inlet openings 86 which connect with an opening 88 in the rear bulkhead 56. Serving as the means for heating incoming air is an electrically energizable heater 90 which is mounted within an annular chamber 92 between the rear bulkhead 56 and perforated rear wall 66 of the tumbling drum. An annular or cylindrical seal 94 defines the peripheral limits of the annular space 92. In this regard, the seal 94 may be of any suitable flexible material such as felt and is mounted in a channel formed by an annular bracket 96 on the rear bulkhead 56. In this fashion, the annular seal 24 extends into relatively rotatable engagement with and bears against a shoulder portion 93 on the rear Wall of the tumbling drum.

Adjacent the front wall 12 of the dryer 16 and connected to the port plate openings 54 is a front duct 100. This duct 109 extends downwardly and channels the air to a duct outlet portion 101 beneath the tumbling drum. It has been determined that air flow temperatures are most stable in the area of the duct portion 101. For this reason temperature responsive devices such as

thermostats

182 and 184 are most effective at this point in the air flow system. Air fiow leaves the front duct 100 through an exhaust port 99 which connects to a flexible conduit 102. This conduit 102 at its opposite end is secured to the inlet fitting 104 of the blower S and, thus, defines an air flow path past the heater 90 and through the tumbling drum 58 to the blower 80. Leading from the blower 80 is an outlet or discharge conduit 1%, generally flexible, which is fastened to a discharge or vent fitting 108 in the sidewall 52 of the dryer. Of course, it should be understood that the discharge fitting 1% may be placed in any suitable position within the dryer 1t) and the flexible discharge conduit 106 connected thereto.

With the foregoing structural arrangement, air flow through the dryer will be as follows. With the motor 82 energized, the blower 80 will be actuated, as will the tumbling drum 58. The operation of the blower 80 will draw in outside air through the ports 86 in the rear wall 50 of the dryer 1%. This air will flow through the bulkhead opening 88 and over the heater 90 adjacent the rear wall of the tumbling drum. After thus being heated by the heater 90, the air will completely fill the annular space 92 and move evenly into the tumbling drum 58 through perforations 61 in the drum Wall 60. Clothing or other material will be tumbling within the drum 58 and the heated currents of air will intermingle with the clothes, picking up the moisture therefrom prior to egress from the tumbling drum through its inlet collar 68. At this point, air is drawn into the lint collecting housing 22 through perforations 30 in the rear housing panel 28. An annular seal 110 circumscribes the outer limits of the housing panel 28 in a manner to engage a beveled annular portion 112 of the port plate 26 when the door 20 is closed. The seal 110 engages the port plate 26 between the port plate openings 24 and the port plate inlet collar 18 to direct all air flow through the lint collecting housing 22. As this heated air passes through the lint collecting housing 22, it will be filtered of foreign matter by the lint collector 38 (FIGURE 2) or the lint collector and burner 40 (FIGURES 1 and 4) and will pass then through the bottom opening or slot 42 in the housing cylindrical wall 34 to a point where the port plate openings 24 provide access into the front duct 100. From this point, air will be drawn through the duct and the flexible conduit 102 to the blower 80. After passing through the blower 80, the discharge conduit 106 may be utilized to direct the vented moisture laden air flow to any suitable discharge fitting 108.

In accordance with one aspect of this invention, flae discharge fitting 108 is provided with a damper 114 (FIG- URE 3) pivotally mounted within the cylindrical duct 168 and actuated by a solenoid 116. This damper 114 has a small port 118 which may be sized to pass a limited amount of air when the damper 114 is closed. Approxi' mately 5 c.f.m. has been found satisfactory to provide the thermostats with enough air to sense correctly the air temperatures and to draw off the products of combustion during lint burning. The effect of the damper 114 is to reduce the air flow through the lint collecting housing 22 during a lint burning operation, as will be described more fully hereinafter. However, the damper 114 is also of value to improve dryer efficiency by reducing air flow from the dryer 10 when it is not carrying the moisture of which it is capable. For instance, during the early stages of a clothes drying cycle, the heat generated by the heater is utilized to warm the components of the dryer 10 and to elevate the temperatures of the wet clothing to be dried. During this preheat stage, the wet clothing is not yet giving up its moisture to the air passing thereover and dry heated air is wasted. When full air flow through the tumbling drum 58 occurs during this preheat period, much heat is wasted and the drying cycle duration unnecessarily prolonged. By closing the damper 114 for a predetermined period at the beginning of the clothes drying cycle, the tumbling drum 58, its fabric contents and the dryer components more quickly reach the temperatures at which the moisture starts to evaporate from the fabric.

In the arrangement of FIGURE 2, the lint collecting housing 22 is shown supporting a simple filter bag 120 in the filter frame 1'21. Any lint entering the housing 22 through the ports 30 is entrapped in the fabriemesh prior to entering the front duct leading to the blower. This fabric may be nylon, wire screen or other suitable mesh adapted for filtering small lint particles from a fluid stream. Since the frame 121 may be removed from the collecting housing 2.2, the lint collecting screen may be cleaned at the conclusion of each drying cycle. Simply filtering lint from an air stream for subsequent manual removal and disposal is recognized as conventional and has been frequently used in the prior art. However, it is known that operators frequently forget to clean the lint filters in a clothes dryer and the efficiency of the dryer suffers. It is a major aspect of this invention to eliminate this undesirable chore by burning lint on the lint collector at a selected point in the drying cycle, thereby obviating the periodic removal of a lint collecting screen.

The lint collecting and burning arrangement 40 of this invention is best seen in FIGURES 4 and 5 and will be clearly described with reference thereto. Where the dryer is to be provided with a lint burner, the support frame 121 for a conventional lint screen 120 is replaced by a support frame 126, having formed thereon the handle 41 to facilitate removal. It should be noted that the lint collecting housing 22 in this embodiment is unchanged from that supporting the lint screen 120. Thus, the opening 36 is adapted to receive either the lint screen support structure 121 or the lint collecting and burning combination 49 carried by the support frame 126. The lint collector and burner 40 is comprised of the arcuate top support member 126 having a generally circular or annular frame 130 fitted within a notch 132 thereof. The frame 130 circumscribes and serves to assemble a lint collector plate 134, a generally spirally wound heater 136 and an oxycatalyst screen 138. The heater 136 may be welded or secured in any suitable means to the collecting plate 134 as at 140. Further the collecting plate 134 is formed from sheet metal having a mass relatively greater than the mass of the screen 138. In this fashion, the plate 134 is heated by the heater 136 rather slowly. This retarded heating for the plate 134 permits the oxycatalyst unit 138 to be warmed to its operating temperature prior to the time at which lint collected on the surface of plate 134 starts to burn. Thus, smoke and odor from the burning process is filtered and eliminated as it passes through the catalyst screen 138 prior to its being discharged to the atmosphere through the discharge fitting 163.

Where the lint collecting and burning arrangement 40 is utilized, an arcuate bottom support portion or seat 142 is placed within the housing 22. A rib 143 extends into an arcuate trough 145 to position the seat which may then be fastened to the housing wall 34 in any suitable fashion as at 147. The seat portion 142 includes an electrical supply terminal block 144 which supports female terminal connections 146. Electrical leads 148 electrically connect the door mounted male plug 44 to the supply terminal block 144. In supporting the heating element 136 on the collecting and burning plate 134, brackets 150 may be utilized to hold the convolutions of the heater in correct relationship. The upper support 126 for the lint burner includes a burner terminal block 152 which cooperates with the supply terminal block 144 in the bottom support member or seat 142. Thus, male connections 154 are aligned with the sockets 146 so that the lint collector and burner assembly 40 is conditioned to be electrically energized when its frame 130 isseated firmly on the bottom support 142 in the lint collecting housing 22;. It should be seen, then, that thelint collector and burner assembly 124 may be slidably removed from its support portion 142 and from the top opening 36 0f the lint collecting housing ".22 simply by grasping the knob 41 and lifting upwardly. The removal of the collector and burner 41 will disconnect the electrical relationship at 154 and 146 so that the entire assembly may be removed for periodic servicing or cleaning.

Another feature of this invention is embodied in a lint burning device which is self cleaning. It should be recognized that a small amount of ash will result from burning the lint collected on plate 134. Over an extended period this ash could accumulate on the burning plate until air flow through the ports 135 in the collector plate 134 is restricted. By the vertical disposition of the lint burner 40 of this invention on the movable door 20 of the dryer, 'the frequent opening and closing of the dryer door 20 maintains the lint collecting plate or surface 134 in a relatively clean condition. The vibration of closing the door will knock any small accumulations of ash from the plate 134 before it has a chance to collect in any substantial amount. At rather infrequent intervals this ash, which will accumulate on the bottom segment of housing wall 34 may be removed. It should be obvious that the ash or residue of a burning process is completely segregated from the dryer air stream. Another advantage of vertically disposing a lint burner on a dryer door arises from the fact that the collecting and burning area may be considerably larger than would be possible at any other location in the dryer air conduit system.

In operation, another aspect of this invention will be described with primary reference to the wiring diagram of FIGURE 6 and the structural teachings hereinabove set forth. For the purposes of controlling the dryer 10 in accordance with the teachings of this invention, the circuit may include a main push'pull on-off switch for starting and stopping a conventional timer motor 162. Interposed in the line from the domestic power supply is a door switch 164 which is closed whenever the dryer access door 20 is closed. The timer motor 162 is utilized to rotate a timer shaft 166 to selectively position a cam actuated timer switch 168 in a conventional indicator light circuit, a cam actuated switch 170 closed by the initiation of a drying cycle to energize the timer motor 162 and timer opened to terminate the cycle, a cam actuated switch 172 to actuate the solenoid 116 for operating the air modulation damper 114, a cam actuated switch 174 for energizing the prime mover or motor 82, a cam actuated switch 176 for energizing the lint burn heaters 136 and a cam actuated switch 178 for energizing the primary dryer heater 90. This primary heater circuit generally may include a switch 180 which is closed whenever the motor 82 is in operation, a safety high limit switch 182 in the heater compartment 92 to interrupt the heater circuit when temperatures within the dryer cabinet 10 exceed certain values, and a temperature responsive thermostat 184 which may be positioned within the front duct 10% to sense the temperature of air leaving the tumbling drum 58. As taught hereinabove, the lint burn heater 136 is also provided with other safety means to prevent the energization thereof when certain undesirable situations exist. For instance, the male prongs 44 are not closed against thereceptacle 46 until the door 20 is closed; and similarlytheheater'terminals 154 do not electrically connect to the terminal block 146 unless and until the lint collector and burner 40 is firmly seated within the lint collecting housing '22. The door switch 164 serves as an additional safety feature in this invention.

To initiate a drying cycle, the operator may push inwardly and rotate in conventional fashion a dryer dial 167 which will close the push-pull switch 160 and the timer motor switch 170. Thus, a drying cycle is initiated. At this point and assuming the dryer door 20 is closed, the timer switches 16%, 172, 174, 176 and 178 will be closed substantially simultaneously. In this way, the indicator lamp 169 may indicate a clothes drying cycle in operation and the motor 82 will be energized to start a circulation of air through the tumbling drum 58. In accordance with one aspect of this invention, the lint which has collected on collector plate 134 during the preceding drying cycle will be burned. For this purpose, the timer switch 172 is closed to energize the solenoid 116 which, in turn, will close the damper 114. Thus, air flow is restricted to that reduced amount passed by the opening 118 in the damper 114. At about the same time, timer switch 176 will energize the lint burn heater 136 to heat the collector plate 134. When the plate 134 reaches ignition temperature, the lint thereon will start to burn or char. During the time that the plate 134 is heating to this ignition temperature, the oxycatalyst screen 138 will be warmed to its operative temperature. Thus, as smoke and odor starts to be evolved from the burning process,

this smoke and odor will be eliminated prior to its passing from the lint collecting housing 22 to the front duct 100 and into the exhaust pipe 106. It is one of the aims of the clothes drying art to dry satisfactorily in as short a time possible. Therefore, it is desirable to design a lint burning process which does not extend the total drying cycle time and which will take advantage of certain inherent dryer characteristics, such as the unproductive warm-up period. For this reason this invention proposes to include the lint burning cycle as the first step in a drying operation. Thus, the lint from a preceding drying cycle is burned during the first step of the drying cycle which followsa time in which the clothes have not yet started giving up their moisture. This is the time when the dryer components are preheating and when the fabric being dried is being raised to a temperature at which it will evaporate its entrained moisture. This is also an advantageous point to burn the lint for the reason that the fabric within the tumbling drum is damp and less prone to ignite from any malfunction of the lint burning apparatus.

At the same time that the lint burning cycle is being accomplished, the timer switch 178 is closed to energize the primary heater 90. Since the air flow through the tumbling drum has been reduced, the eifect of heater 90 will be more pronounced and both the dryer components and the damp fabric to be dried will increase quickly in temperature to a point at which drying will commence. Of course, it is within the purview of this invention to withhold ignition of the primary heater 90 until the lint burning cycle is completed. In any event, the safety thermostat 182 will guard against excessive temperatures within the tumbling drum.

After a sufi'icient period of approximately three minutes in which the accumulated lint is burned to a fine ash on the collecting plate 134, the timer switches 172 and 176 are opened. This opens the restricting damper 114 and deenergizes the lint burn heater 136 to terminate the lint burn cycle. It should be noted however that timer switch 176 may be opened slightly ahead of the timer switch 172 to insure that all smoke and odor has been eliminated before full air flow is restored. Thereafter the drying cycle will continue in a timed fashion with the energization of the primary heater 90 being controlled by the temperature regulating thermostat 184-. During this time, the tumbling drum will continue to rotate and the lint evolved during the drying process will be collected on the plate 134 of the lint collector and burner assembly 40. The drying cycle may be completed with a no-heat portion in which the timer switch 178 is opened to deenergize the heater 90. For approximately the last ten minutes of a drying cycle, the timer switches 168, 170 and 174 will be the only timer switches in a closed position. At the conclusion of this no-heat tumbling operation in which the clothes are cooled to a comfortable touch temperature, all of the timer switches will be moved to their open position and the timing cycle completed. It should be obvious that the lint collecting on plate 134 during this last described cycle will be burned as the first step in the next succeeding drying cycle.

It should now be seen that an improved lint burning arrangement has been provided for a clothes dryer wherein the lint burning arrangement is vertically mounted in a dryer door to prevent accumulation of burned lint ash. Further, the lint burning cycle is initiated as the first step in a drying cycle to take advantage of a period in which the dryer is normally cold and not efiective to dry fabrics in the tumbling drum. The advantage of the additional lint burner heat and the reduced air flow through the dryer in the lint burning cycle further aids in accelerating the dryer to effective drying temperatures and in shortening the total time for a drying cycle.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adapted.

What is claimed is as follows:

1. In combination with a hingedly mounted dryer door, a lint collector and burner adapted for vertical mounting in said dryer door comprising, a first removable support member having a first terminal block portion, a lint collecting plate, a heater in juxtaposition to said collecting plate and an oxycatalyst screen in juxtaposition to said heater, said heater being electrically connected to said terminal block portion, a second support member mounted on said door and formed complementarily to said first support member and having a second terminal block portion electrically connected to a source of energy, whereby when said first support member is placed adjacent said second support member, said heater is conditioned for energization.

2. In combination with a clothes dryer having a cabinet, a tumbling drum and means for circulating a stream of heated air through said tumbling drum, an access means in said cabinet for said tumbling drum, conduit means connecting said tumbling drum to said circulating means, duct means connecting said circulating means to the atmosphere, damper means in said duct means for selectively restricting said stream of heated air during a single dryer operating cycle, nonhorizontal means on said access means for collecting lint in said conduit means, and means for burning said lint on said collecting means prior to drying clothes in said tumbling drum, said access means and said collecting means being movably mounted to said cabinet for dislodging the lint residue from said burning whenever said access means is moved.

3. In combination with a clothes dryer having a tumbling chamber and means for circulating sequentially a first and second stream of air through said tumbling chamber during a single clothes drying cycle, an access means for said tumbling chamber for loading and unloading clothes from said tumbling chamber, means forming a conduit connecting said tumbling chamber to said circulating means, nonhorizontal means on said access means for collecting lint in said conduit means, and means for burning said lint on said collecting means during the circulation of said first stream of air and for drying said clothes during the circulation of said second stream of air.

4. In combination with a dryer for damp fabrics having a cabinet, a tumbling drum in said cabinet having a drum inlet and a drum outlet, a port plate having a collar in axial alignment with said drum outlet and a port plate opening interposed between said cabinet and said tumbling drum, and means for circulating air from said drum nlet to said port plate opening: a hingedly mounted outer lmperforate door panel having an open position and a closed position, an inner perforate door panel, a support member having an insert opening and an exhaust opening therein and connecting said inner and outer door panels, said inner perforate door panel cooperating with said port plate between said collar and said port plate opening when said outer door panel is in said closed position to intercept air circulating from said drum outlet, a lint collector and burner adapted for removable installation through said insert opening into intercepting air flow relationship with said perforate door panel and said exhaust opening, said lint collector and burner including means for collecting lint from said tumbling drum, means for burning the lint so collected whereby smoke and odor are generated, and means to eliminate the smoke and odor so generated, and a timer for controlling a clothes drying cycle and for selectively energizing said lint burning means only during a limited period of time at the beginning of the drying cycle.

5. In combination with a clothes dryer having a cabinet, a tumbling drum in said cabinet having a drum inlet and a drum outlet, a port plate having a collar in axial alignment with said drum outlet and a port plate opening interposed between said cabinet and said tumbling drum, and

means for circulating air from said drum inlet to said port plate opening: a pivotally mounted outer irnperforate door panel having an open position and a closed position, an inner perforate door panel, a support member having an insert opening and an exhaust opening therein and connecting said inner and outer door panels, said inner perforate door panel cooperating with said port plate between said collar and said port plate opening when said outer door panel is in said closed position to intercept air circulating from said drum outlet, a lint collector and burner in intercepting air flow relationship with said perforate door panel and said exhaust opening and removably mounted through said insert opening, said lint collector and burner including means for collecting lint from said tumbling drum, means for burning the lint so collected whereby smoke and odor are generated, means to elimimate the smoke and odor so generated and means for conditioning said lint burning means for energization only when said lint collector and burner is in said intercepting air flow relationship, and timing means for controlling a clothes drying cycle and for selectively energizing said lint burning means and said smoke and odor eliminating means only during a limited period of time at the beginning of said clothes drying cycle.

6. A control system for a clothes dryer defining a drying chamber and having means for circulating air through said chamber, means downstream from said drying chamber for collecting lint from said air, a primary heater for drying said clothes, a lint burning heater for burning the lint collected during said drying and means for selectively reducing the air circulating over said collecting means comprising, a first switch for controlling said lint burner, a second switch for controlling said reducing means, a third switch for controlling said primary heater, circuit means connecting said first switch to said lint burner, said second switch to said reducing means and said third switch to said primary heater, and timing means for controlling said switches in a manner to effect said burning lint in a reduced air circulation before said primary heater is energized to dry said clothes.

7. In combination, a dryer for damp fabrics wherein foreign matter is evolved comprising, a casing having an opening, a door for closing said opening, and self-cleaning means on said door for burning said foreign matter, said means including a substantially vertical face portion for trapping said foreign matter, said face portion being jostled by the movement of said door to keep said means free of the residue of said burning.

8. A door mounted lint collecting and burning arrangement for a clothes dryer having a cabinet, at tumbling drum in said cabinet having a drum inlet and a drum outlet, a port plate having a collar in axial alignment with said drum outlet and a port plate opening interposed between said cabinet and said tumbling drum and means for circulating air from said drum inlet to said port plate opening comprising, a vertically pivotally mounted outer imperforate door panel having an open position and a closed position, an inner perforate door panel, a generally cylindrical support member having an insert opening and an exhaust opening therein and connecting said inner and outer door panels, said inner perforate door panel cooperating with said port plate between said collar and said port plate opening when said outer door panel is in said closed position to intercept air circulating from said drum outlet, a lint collector and burner removably mounted through said insert opening into intercepting air flow relationship with said perforate door panel and said exhaust opening, said lint collector and burner including means for collecting lint from said tumbling drum, means for burning the lint so collected whereby smoke and odor are generated, means activated by said lint burning means to eliminate the smoke and odor so generated, means for conditioning said lint burning means for energization only when said lint collector and burner is in said intercepting air flow relationship and means for conditioning said lint burning means for energization only when said outer door panel is in said closed position, means for sealing between said outer door panel and said cabinet, means for sealing between said inner door panel and said port plate, and timing means for controlling a clothes drying cycle and for se lectively energizing said lint burning means on during a limited period of time at the beginning of said clothes drying cycle.

9. A clothes dryer including a casing defining a drying chamber and having an air inlet and an air outlet, air impelling means for circulating air through said chamber from said inlet to said outlet, lint collecting means communicating with said air outlet and located in the path of air circulating from said chamber, means for burning the lint collected by said lint collecting means, and means synchronized with said burning means for reducing the air flow past said lint collecting means while said lint burning means is effective only during a limited period of time at the beginning of the drying cycle.

10. A fabric dryer including a casing defining a drying chamber and having a fluid medium inlet opening and a fluid medium outlet opening therein, lint collecting means communicating with said outlet opening, means for circulating a fluid medium sequentially through said drying chamber and into complete lint collecting relationship with said lint collecting means, means for reducing the fluid medium How on said lint collecting means, means for burning the lint collected, and synchronizing means for operating said burning means only at a fixed interval during a period of reduced fluid medium flow on said lint collecting means at the beginning of the drying cycle.

11. A clothes dryer comprising a casing defining a drying chamber and having an air inlet opening and an air outlet opening therein, a lint collector housing communicating with said air outlet, lint collector means in said housing, an air exhaust duct for receiving air from said housing, means for circulating air sequentially through said drying chamber, said housing and said exhaust duct, means for burning the lint collect-ed on said lint collector means, means for altering the products of combustion from said lint burning means, means for reducing the volume of air circulated past said lint collector means, and means for concurrently actuating said burning means and said air circulation reducing means only during a limited period of time at the beginning of the drying cycle.

12. A clothes dryer including a drying chamber, heating means for said chamber, an air inlet and an air outlet for said dryer communicating with said chamber, air impelling means for circulating air through said chamber from said inlet to said outlet, lint collecting means located between said inlet and outlet in the path of air circulating therebetween, means for burning the lint collected by said lint collecting means, first and second switch means connected respectively to said lint burning means and said heating means and closable respectively for energizing said lint burning means and said heating means, and timing means actuatably connected to said first and second switch means for concurrently closing said first and second switch means to energize said lint burning means and said heating means during a limited period of time at the beginning of the drying cycle, said timing means subsequently opening said first switch means to terminate said lint burning while maintaining said second switch means closed to continue said drying cycle.

13. A control system for a clothes dryer defining a drying chamber and having means for circulating air through said chamber, means downstream from said drying chamber for collecting lint from said air, a primary heater for heating said air sequentially to preheat said dryer and dry said clothes and a lint burner for burning 1 1 the lint collected only during the preheating of said dryer comprising, a first switch means closable to energize said lint burner in a lint burning cycle of one duration, at second switch means closable for energizing said primary heater in a dryer preheating and clothes drying cycle of another duration longer than said one duration, circuit means connecting said first switch means to said lint burner and said second switch means to said primary heater, and timing means for controlling said switch means to effect said lint burning cycle at the start of said dryer preheating and clothes drying cycle, said timing means including means for concurrently closing said first and second switch means for said one duration to initiate both of said cycles before automatically opening only said first switch means to terminate only said lint burning cycle.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain Mar. 31,

OTHER REFERENCES 15 Speed Queen Publication, Form No. 467, received by- Patent Ofiice December 14, 1953.