Air actuated automatic lint screen cleaning system for dryer

• US 4,700,492 A
• Filed: 02/05/1986
• Issued: 10/20/1987
• Est. Priority Date: 02/05/1986
• Status: Expired due to Fees

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Werner, Kurt, Carr, Keith E., Brenner, Robert A., Malchow, Gregory L.
• Primary Examiner(s): Makay, Albert J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/826,181
• Time in Patent Office: 622 Days
• Field of Search: 34/82, 34/85, 34/133, 34/32, 55/294
• US Class Current: 34/403
• CPC Class Codes: D06F 2105/34 Filtering, e.g. control of lint removal devices
• CPC Class Codes: D06F 58/22 Lint collecting arrangements
• CPC Class Codes: D06F 58/45 Cleaning or disinfection of machine parts, e.g. of heat exchangers or filters

Abstract

An air actuated lint removing system for cleaning lint filters in clothes dryers includes means for moving the lint filter and an air flow directing means with respect to one another to remove accumulated lint, and lint transporting means to move the lint to a lint collection reservoir.

Claims

1. A method for cleaning a circular lint screen in a clothes dryer including a blower for generating a first air flow through said circular lint screen, comprising:

accumulating lint on a first side of said circular lint screen by said first air flow during operation of said dryer;

directing a restricted second air flow through said lint screen in a direction opposite to said first air flow to remove lint accumulated on said first screen side, said restricted second air flow being directed through a narrow radially extending region of said circular lint screen from substantially the center of said screen to adjacent the edge of said screen, said radially extending region through which said second air flow is directed being wider adjacent said edge of said screen than at said center of said screen;

moving said restricted second air flow rotationally relative to said lint screen to cause oppositely directed air flow through substantially all of said lint screen in a predetermined time period;

transporting lint removed from said lint screen to a lint reservoir; and

storing lint that has been transported within said lint reservoir.

2. An automatic lint removal system for use in an automatic clothes dryer having a lint collecting screen on which lint particles are accumulated during operation of said dryer, comprising:

means for generating a negative air pressure differential across said screen to cause air flow through said lint collecting screen to effect removal of said accumulated lint particles;

means for directing the air flow caused by said pressure differential generating means, said directing means including a vacuum arm defining an opening adjacent the lint collecting screen;

means for moving said air flow directing means with respect to said lint screen to direct said air flow through substantially all of said lint screen in a predetermined interval;

means for transporting lint particles removed from said lint collecting screen;

a lint storage reservoir into which lint particles removed from said lint screen are deposited by said lint transporting means; and

an optical sensor mounted at said lint storage reservoir and connected to determine when said lint storage reservoir becomes full.

3. An automatic lint removal system for use in an automatic clothes dryer having a circular lint collecting screen on which lint particles are accumulated by an air flow in a first direction during operation of said dryer, comprising:

means for generating an air pressure differential across said screen to cause a negative air flow in a second direction opposite to said first direction through said lint collecting screen to effect removal of said accumulated lint particles;

means for directing said negative air flow caused by said pressure differential generating means, said directing means including a vacuum arm defining an opening adjacent said lint collecting screen and having a cylindrical mounting sleeve;

means for moving said directing means with respect to said lint screen to direct said negative air flow through substantially all of said lint screen in a predetermined interval, said moving means including;

a selectively operating motor; and

a linkage connected between said motor and said vacuum arm to enable said motor to rotate said vacuum arm when said motor is operated, said linkage including a geared bushing around said cylindrical mounting sleeve of said vacuum arm and a speed reduction mechanism connected between said motor and said geared bushing to transmit the rotational energy of said motor to said vacuum arm;

means for transporting lint particles removed from said lint collecting screen; and

a lint storage reservoir into which lint particles removed from said lint screen are deposited by said lint transporting means.

4. A system as claimed in claim 3, wherein an air flow cross-section area at said opening is less than an air flow cross-section area at an interior of said vacuum arm, and said interior arm flow cross-section area is less than an air flow cross-section area at an outlet of said vacuum arm.

5. An automatic lint removal system for use in an automatic clothes dryer having a lint collecting screen on which lint particles are accumulated during operation of said dryer, comprising:

means for generating an air pressure differential across said screen to cause air flow through said lint collecting screen to effect removal of said accumulated lint particles;

means for moving said air pressure differential generating means with respect to said lint screen to direct said air flow through substantially all of said lint screen in a predetermined interval;

means for transporting lint particles removed from said lint collecting screen;

a lint storage reservoir into which lint particles removed from said lint screen are deposited by said lint transporting means;

said pressure differential generating means generating a negative air pressure at a surface portion of said lint collecting screen;

means disposed adjacent a lint collecting side of said lint collecting screen for directing the air flow caused by said negative air pressure, said air flow directing means defining an opening adjacent said lint collecting screen;

said pressure differential generating means including a vacuum blower and a lint conduit in communication with said vacuum blower;

said air flow directing means including a vacuum arm in communication with said lint conduit, said vacuum arm being selectively movable and mounted for rotation in said dryer adjacent said lint collecting screen;

said lint collecting screen being stationary and substantially circular in shape; and

a screen engaging face of said vacuum arm including a beveled surface extending adjacent a first rotationally directed side of said opening.

6. An automatic lint removal system for use in an automatic clothes dryer having a lint collecting screen on which lint particles are accumulated during operation of said dryer, comprising:

means for generating an air pressure differential across said screen to cause air flow through said lint collecting screen to effect removal of said accumulated lint particles;

means for moving said air pressure differential generating means with respect to said lint screen to direct said air flow through substantially all of said lint screen in a predetermined interval;

means for transporting lint particles removed from said lint collecting screen;

a lint storage reservoir into which lint particles removed from said lint screen are deposited by said lint transporting means;

said pressure differential generating means generating a negative air pressure at a surface portion of said lint collecting screen;

means disposed adjacent a lint collecting side of said lint collecting screen for directing the air flow caused by said negative air pressure, said air flow directing means defining an opening adjacent said lint collecting screen;

said pressure differential generating means including a vacuum blower and a lint conduit in communication with said vacuum blower;

said air flow directing means including a vacuum arm in communication with said lint conduit, said vacuum arm being selectively movable and mounted for rotation in said dryer adjacent said lint collecting screen;

said lint collecting screen being stationary and substantially circular in shape; and

said opening being wider at a radially distant end than at a centrally disposed end.

7. In a fabric dryer having a drum for tumbling a fabric load and a blower for circulating heated air through said load to an air discharge passage and for defining a first air flow direction, a lint screen cleaning and lint storage device, comprising:

a removable circular filter screen mounted in said air discharge passage for accumulating lint on a first lint collecting surface;

a vacuum arm having a face mounted adjacent said first screen surface, said face defining a shaped opening through which lint is drawn from said first screen surface, one end of said vacuum arm extending adjacent an edge of said circular filter screen and a portion of said vacuum arm being disposed adjacent a center of said circular filter screen, said centrally disposed portion including a vacuum arm outlet;

a motor connected to rotate said vacuum arm to move said one vacuum arm end along the edge of said circular filter screen;

a lint conduit having at a first end connected in communication with said vacuum arm outlet;

a lint blower in communication with a second opposite end of said lint conduit and operable to draw air and lint through said vacuum arm opening and said lint conduit;

a lint storage reservoir in communication with said vacuum blower into which lint and air are blown;

a selectively openable access means in said lint storage reservoir for removing lint from said reservoir; and

a second filter mounted within said lint storage reservoir for retaining lint within said reservoir said opening extending from said one end of said arm to said centrally disposed portion of said vacuum arm and said opening being wider at said one end than at said centrally disposed portion.

8. An automatic lint remover for use in a fabric dryer having a blower for generating an outlet air stream in a first direction, comprising:

a continuous belt filter screen mounted for movement past said outlet air stream to accumulate lint on a first side of said belt filter screen;

a stationary air nozzle mounted to direct an air jet through said continuous belt filter screen in a second direction opposite to said first direction to separate lint from said filter screen;

means for removing lint from said filter screen mounted at said first side of said filter screen, said removing means being mounted opposite said air nozzle in the flow path of said air jet, said removing means including;

a scaper adjacent said filter screen,

a rotatable auger mounted adjacent said scraper to engage lint scraped from said filter screen, and

means for rotating said auger;

a motor coupled to move said continuous belt filter screen past said nozzle;

a pressure sensor mounted to detect a predetermined pressure drop across said filter screen at said outlet air stream to trigger operation of said motor;

a lint storage reservoir in communication with said rotatable auger into which lint is carried by said auger; and

an openable door providing access to said lint storage reservoir through which accumulated lint is removed.

9. An automatic lint removing and collecting apparatus for use in an automatic fabric dryer having an outlet duct from a dryer compartment through which lint laden air passes, comprising:

a rotatable cylindrical filter screen mounted at said outlet duct to filter lint from lint laden air onto an exterior surface of said cylindrical filter screen;

a vacuum arm fixedly mounted adjacent said exterior surface of said filter screen and defining an opening extending along the length of said cylindrical screen through which lint is drawn;

a motor connected to rotate said cylindrical filter screen about a longitudinal axis;

a vacuum blower having an input in communication with said vacuum arm and being operable to generate an air flow into said opening;

a lint storage reservoir in communication with an output of said vacuum blower into which lint is blown by said blower;

a filter bag disposed within said lint storage reservoir and connected to said output of said vacuum blower to retain lint blown into said lint storage reservoir by said vacuum blower;

a first sensing means mounted for sensing when the lint retained in said filter bag has filled said filter bag; and

a second sensing means for sensing lint build-up on said filter screen by transmitting a signal through said filter, said second sensing means connected to initiate operation of said vacuum blower and said screen motor upon sensing a predetermined build-up of lint on said filter screen.