Light-weight self-propelled vacuum cleaner

Abstract

A vacuum cleaner power head ( 40 ) for vacuum cleaning and having two counter rotating agitators 52 and 54 . Motor ( 60 ) rotates agitators ( 52 ) and ( 54 ) through transmission ( 70 ), and also rotates suction fan ( 65 ) to provide suction air to the rotary brush agitators. Exterior housing 48 and inner housing ( 49 ) provide air suction passageways to direct suction air through fan ( 65 ) and out of the housing to a dirt collection bag ( 34 ). Self-propelled function is provided by using user force on handle ( 32 ) to create differential contact friction between the two counter-rotating rotary brush agitators so that a net traction force is generated that propels power head ( 40 ) in the direction the user is pushing.

1. A vacuum power head for cleaning, comprising:
 a) a housing having a front and rear portion;   b) an agitator assembly with a front rotary agitator and a rear rotary agitator;   c) an electric motor;   d) a power transfer means for transferring rotary power from said electric motor to said front and rear rotary agitators;   e) a suction conduit having an entrance and an output port;   f) a hose wand;   g) a lever arm connected between said hose wand and said agitator assembly for amplifying the force exerted by the hose wand on the agitator assemble;   h) an adjustment means associated with said lever arm and said agitator assembly for generating a net traction force on said front and rear rotary agitators when in contact with a surface and said net traction force responsive to force exerted on said hose wand by a user;   i) wherein, said suction conduit forms a continuous air channel between at least one of the rotary agitators and said output port;   j) wherein, said output port is designed to accept the hose wand, whereby dirt and dust agitated by the rotary agitators can be removed from the power head;   k) wherein, said front and rear rotary agitators rotate in opposite directions when powered by said power transfer means, and   l) wherein, said net traction force is in the direction of the front portion of the housing when the user is pushing the hose wand forward and said net traction force is in the direction of the rear portion of the housing when the user is pulling backward on the hose wand, whereby the vacuum power head provides a self-propelled function.   
     
     
       2. The vacuum power head in  claim 1 , further including;
 a suction fan for producing a suction airflow;   a handle;   a dirt collection bag; and   wherein the hose wand defines an air channel between said dirt collection bag and said output port for conducting the suction airflow to said dirt collection bag from said output port;   wherein, said suction fan is connected to said electric motor for providing said suction airflow along said continuous air channel, whereby dirt sucked up by the airflow can travel to said dirt collection bag.   
     
     
       3. The vacuum power head in  claim 1 , wherein;
 said adjustment means moves both front and rear rotary agitators with respect to the housing and around an axis between the agitators to provide said self-propelled function.   
     
     
       4. The vacuum power head in  claim 1 , wherein;
 said adjustment means comprises an adjustment assembly for pivoting one of the rotary agitator into greater and lesser contact with the surface to provide the differential traction force for propelling the vacuum power head forward and backward.   
     
     
       5. The vacuum power head in  claim 1 , wherein;
 said agitator assembly is defined by said front and rear rotary agitator mounted substantially next to each other and pivotal about an axis between them.   
     
     
       6. The vacuum power head in  claim 5 , wherein;
 said front and rear rotary agitators are both mounted substantially in the front portion of the vacuum power head.   
     
     
       7. The vacuum power head in  claim 1 , wherein;
 said agitator assembly is defined by said electric motor and said front and rear rotary agitator mounted substantially together so they are moved as a unit by said lever arm.   
     
     
       8. The vacuum power head in  claim 1 , wherein;
 said lever arm is defined by a pivot arm connected to only one rotary agitator and responsive to said user movement to raise and lower that rotary agitator to provide the differential traction force for said self-propelled function.   
     
     
       9. The vacuum power head in  claim 8 , wherein;
 said agitator assembly is defined by said front and rear rotary agitator mounted substantially next to each other and pivotal about an axis between them.   
     
     
       10. The vacuum power head in  claim 1 , wherein;
 said lever arm is connected to a support roller for raising and lowering either the front or rear portion of the housing to provide the differential traction force on the front and rear agitators which are mounted to the housing for providing said self-propelled function.   
     
     
       11. A vacuum cleaner power head for cleaning a surface, comprising:
 a) a housing having a front and rear portion;   b) a front rotary agitator and a rear rotary agitator;   c) an electric motor;   d) a power transfer means for transferring rotary power from the electric motor to the front and rear rotary agitators;   e) a suction conduit having an entrance and an output port;   f) a hose wand;   g) a lever arm responsive to the hose wand;   h) an adjustment means associated with the lever arm and rotary agitators for adjusting the contact force of at least one of the rotary agitators with respect to the surface;   i) wherein, the suction conduit forms a continuous air channel between at least one of the rotary agitators and the output port;   j) wherein, the hose wand is pivotally connected with respect to the housing and in communication with the continuous air channel, whereby dirt and dust agitated by the rotary agitators can be removed from the power head through the hose wand;   k) wherein, the front and rear rotary agitators rotate in opposite directions when powered by the power transfer means, and   l) wherein, the adjustment means provides a net traction force in the direction of the front portion of the housing when the user is pushing the hose wand forward and wherein the net traction force is in the direction of the rear portion of the housing when the user is pulling backward on the hose wand, whereby the vacuum cleaner power head provides a self-propelled function.   
     
     
       12. The vacuum cleaner power head in  claim 11 , further including;
 a suction fan connected to the electric motor for producing a suction airflow; and   a dirt collection bag connected to the hose wand;   wherein, the suction conduit defines a continuous air channel from at least one of the rotary agitators, through the suction fan, and into the hose wand, and   wherein the hose wand communicates the suction airflow between the output port and the dirt collection bag, whereby dirt sucked up by the suction airflow is carried to the dirt collection bag.   
     
     
       13. The vacuum cleaner power head in  claim 11 , wherein,
 said adjustment means moves both front and rear rotary agitators with respect to the housing and around an axis between the agitators to provide said self-propelled function.   
     
     
       14. The vacuum cleaner power head in  claim 11 , wherein,
 said front and rear rotary agitators are both mounted substantially in the front portion of the vacuum cleaner power head.   
     
     
       15. The vacuum cleaner power head in  claim 11 , wherein,
 the rotary agitators and the housing are fixed in relationship to each other, wherein the adjustment means pivots the housing and the rotary agitator with respect to the surface to adjust the net traction force for propelling the vacuum cleaner power head forward and backward.   
     
     
       16. The vacuum cleaner power head for cleaning a surface, comprising:
 a) a housing having a front and rear portion;   b) a hose wand pivotally mounted to the vacuum cleaner power head;   c) an electric motor;   d) a suction fan mechanically driven by the electric motor;   e) a front rotary agitator and a rear rotary agitator, both rotatably mounted to a fixed position on the housing;   f) a power transfer means for transferring rotary power from the electric motor to the front and rear rotary agitators, wherein the two rotary agitators rotate in opposite directions;   g) a suction conduit designed to accept a hose wand, wherein the suction conduit defines a continuous air channel from at least one of the rotary agitators, through the suction fan, and out of the vacuum cleaner power head through the hose wand, whereby dirt and dust agitated by the rotary agitators can be removed from the vacuum cleaner power head through the hose wand and into a dirt collection means connected to the hose wand, and   h) an adjustment means defined on the vacuum cleaner power head and responsive to force applied to the hose wand by a user for adjusting the relative position of the front and rear rotary agitators with respect to the surface;   i) wherein, the front and rear rotary agitators rotate in opposite directions when powered through the power transfer means, and   j) wherein the adjustment means provides a net traction force in the direction of the front portion of the housing when the user is pushing the hose wand forward and the net traction force is in the direction of the rear portion of the housing when the user is pulling backward on the hose wand, whereby the vacuum cleaner power head provides a self-propelled function.   
     
     
       17. The vacuum cleaner power head in  claim 16 , wherein, the electric motor, suction fan, and front and rear rotary agitators are all mounted at a substantially fixed location within the vacuum cleaner power head, whereby the adjustment of the relative positions of the front and rear portions of the housing, also adjusts the relative positions of the front and rear rotary agitators with respect to the surface. 
     
     
       18. The vacuum cleaner power head in  claim 17 , wherein, the adjustment means comprises by a support wheel comprising a pivot bearing mounted to the vacuum cleaner power head, wherein the vacuum cleaner power head pivots around the pivot bearing relative to the surface for adjusting the relative position of the front and rear rotary agitators with respect to the surface. 
     
     
       19. A power head for a surface cleaning apparatus, the power head comprising:
 a housing;   an agitator assembly having rotary agitators;   an electric motor coupled to the rotary agitators for rotating the rotary agitators; and   an adjustment member associated with the housing and the agitator assembly, the adjustment member configured to change a position of the agitator assembly by pivoting the housing when the housing is pushed by a user to generate a net traction force from the rotary agitators on a surface, wherein the net traction force is in at least one of a first direction when the housing is pushed in the first direction to cause the adjustment member to move and pivot the housing toward the first direction or in an opposite second direction when the housing is pushed in the second direction to cause the adjustment member to move and pivot the housing toward the second direction.   
     
     
       20. The power head of claim 19, further comprising a handle pivotally coupled with the housing, the handle configured to be moved by a user to pivot the housing in the first direction or the second direction, wherein the adjustment member at least one of pivots the housing in the first direction when the user engages the handle to push the housing in the first direction or pivots the housing in the second direction when the user engages the handle to push the housing in the second direction. 
     
     
       21. The power head of claim 19, wherein the adjustment member is configured to raise at least one of the rotary agitators to generate the net traction force when the adjustment member moves on the surface. 
     
     
       22. The power head of claim 19, wherein relative positions of the housing and the rotary agitators remain substantially constant as the adjustment member moves to change a direction of the net traction force. 
     
     
       23. The power head of claim 19, wherein the adjustment member comprises a wheel rotatably mounted in the housing,, the wheel configured to at least partially roll on the surface to raise or lower one or more of the rotary agitators when the net traction force is changed. 
     
     
       24. A surface cleaning apparatus comprising:
 a housing;   a handle coupled to the housing;   agitator brushes configured to engage a surface as the housing moves relative to the surface;   a motor operatively coupled with the agitator brushes to rotate the agitator brushes; and   an adjustment member associated with the housing and the agitator brushes, the adjustment member configured to pivot the housing to change a position of at least one of the agitator brushes to generate a net traction force on the surface when the handle is pushed to move the adjustment member on the surface, wherein the net traction force is in at least one of a first direction when the handle is pushed in the first direction or in an opposite second direction when the handle is pushed in the second direction, the handle configured to cause the adjustment member to pivot the housing in at least one of the first direction when the handle is pushed in the first direction or the second direction when the handle is pushed in the second direction.   
     
     
       25. The surface cleaning apparatus of claim 24, wherein the handle is configured to be pushed by a user to move the housing in the first direction or the second direction, and wherein the adjustment member is operatively coupled with the handle such that pushing the handle in the first direction or the second direction moves the adjustment member in the corresponding first direction or second direction and causes the adjustment member to rotate the housing toward the corresponding first direction or second direction. 
     
     
       26. The surface cleaning apparatus of claim 24, wherein the adjustment member raises at least one of the agitator brushes to generate the net traction force when the adjustment member moves on the surface. 
     
     
       27. The surface cleaning apparatus of claim 24, wherein relative positions of the housing and the agitator brushes remain substantially constant as the adjustment member moves to change a direction of the net traction force. 
     
     
       28. The surface cleaning apparatus of claim 24, wherein the adjustment member comprises a wheel rotatably mounted to the housing, the wheel at least partially rolling on the surface to raise or lower one or more of the agitator brushes to change the net traction force. 
     
     
       29. A method comprising:
 coupling an agitator assembly with a motor, the agitator assembly including rotary agitators and at least partially disposed in a housing of a surface cleaning apparatus, the motor configured to rotate the rotary agitators; and   coupling an adjustment member with the housing and the agitator assembly, the adjustment member configured to change a position of the agitator assembly by pivoting the housing when the housing is pushed by a user to generate a net traction force from the rotary agitators on a surface,   wherein the net traction force is in at least one of a first direction when the housing is pushed in the first direction to cause the adjustment member to move and pivot the housing toward the first direction or in an opposite second direction when the housing is pushed in the second direction to cause the adjustment member to move and pivot the housing toward the second direction.   
     
     
       30. The method of claim 29, further comprising pivotally coupling a handle with the housing such that the handle is configured to be moved by a user to pivot the housing in the first direction or the second direction, wherein the adjustment member at least one of pivots the housing in the first direction when the user engages the handle to push the housing in the first direction or pivots the housing in the second direction when the user engages the handle to push the housing in the second direction. 
     
     
       31. The method of claim 29, wherein coupling the adjustment member includes connecting the adjustment member with the agitator assembly such that the adjustment member is configured to raise at least one of the rotary agitators to generate the net traction force when the adjustment member moves on the surface. 
     
     
       32. The method of claim 29, wherein coupling the adjustment member includes connecting the adjustment member with the housing and the agitator assembly such that relative positions of the housing and the rotary agitators remain substantially constant as the adjustment member moves to change a direction of the net traction force. 
     
     
       33. The method of claim 29, wherein coupling the adjustment member includes rotatably mounting a wheel in the housing that is configured to at least partially roll on the surface to raise or lower one or more of the rotary agitators when the net traction force is changed. 
     
     
       34. A method comprising:
 coupling a handle to a housing of a surface cleaning apparatus;   coupling a motor with agitator brushes that are configured to engage a surface as the housing moves relative to the surface, the motor coupled with the agitator brushes in order to rotate the agitator brushes; and   coupling an adjustment member with the housing and the agitator brushes such that the adjustment member is configured to pivot the housing to change a position of at least one of the agitator brushes to generate a net traction force on the surface when the handle is pushed to move the adjustment member on the surface,   wherein the net traction force is in at least one of a first direction when the handle is pushed in the first direction or in an opposite second direction when the handle is pushed in the second direction, the handle configured to cause the adjustment member to pivot the housing in at least one of the first direction when the handle is pushed in the first direction or the second direction when the handle is pushed in the second direction.   
     
     
       35. The method of claim 34, wherein coupling the handle includes coupling the handle to the housing such that the handle is configured to be pushed by a user to move the housing in the first direction or the second direction, and wherein coupling the adjustment member includes coupling the adjustment member with the handle such that pushing the handle in the first direction or the second direction moves the adjustment member in the corresponding first direction or second direction and causes the adjustment member to rotate the housing toward the corresponding first direction or second direction. 
     
     
       36. The method of claim 34, wherein coupling the adjustment member includes coupling the adjustment member to the agitator brushes such that the adjustment member raises at least one of the agitator brushes to generate the net traction force when the adjustment member moves on the surface. 
     
     
       37. The method of claim 34, wherein coupling the adjustment member includes coupling the adjustment member with the housing and the agitator brushes such that relative positions of the housing and the agitator brushes remain substantially constant as the adjustment member moves to change a direction of the net traction force. 
     
     
       38. The method of claim 34, wherein coupling the adjustment member includes rotatably mounting a wheel to the housing such that the wheel at least partially rolls on the surface to raise or lower one or more of the agitator brushes to change the net traction force.