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  portions;  
 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  a force exerted by the hose wand on the agitator assemble  assembly;  
 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 the 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; and 
 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  net 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  said front and rear rotary agitators. 
     
     
       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  said front and rear rotary agitators 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  agitators and responsive to said  user movement to raise and lower that rotary agitator to provide the differential  net 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  agitators mounted substantially next to each other and pivotal about an axis between them  said front and rear rotary agitators. 
     
     
       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  portions of the housing to provide the differential  net 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  portions;  
 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; and 
 h)  an adjustment means associated with the lever arm and rotary agitators for adjusting the  a 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  a 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  A vacuum cleaner power head for cleaning a surface, comprising:
 a)  a housing having a  front and rear portion  portions;  
 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  a 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  a 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 having front and rear portions;        a handle pivotally coupled with the housing;        an agitator assembly with a front rotary agitator and a rear rotary agitator;        an electric motor coupled to the front and rear rotary agitators for rotating the front and rear rotary agitators in opposing directions; and        an adjustment member joined with the housing, the adjustment member including a wheel that rotates independent of rotation by the front and rear rotary agitators, the adjustment member pivoting the housing to generate a net traction force from the front and rear rotary agitators on a surface that propels the housing along the surface, wherein the net traction force is in a front direction toward the front portion of the housing when the user is pushing the handle forward and the net traction force is in a rear direction toward the rear portion of the housing when the user is pulling backward on the handle.     
     
     
       20. The power head of  claim 19 , wherein the housing pivots in response to the pushing or pulling of the handle to raise one of the front and rear rotary agitators and lower another one of the front and rear rotary agitators relative to the surface to change the net traction force. 
     
     
       21. The power head of  claim 19 , wherein relative positions of the housing and the front and rear rotary agitators remain substantially constant as the housing pivots to change a direction of the net traction force. 
     
     
       22. The power head of  claim 19 , wherein the housing is an exterior housing and the wheel of the adjustment member is rotatably mounted to an inner housing that is disposed within and joined to the exterior housing, the wheel translating the pushing or pulling on the handle into pivoting of the exterior housing about the wheel in order to change a direction of the net traction force. 
     
     
       23. The power head of  claim 19 , wherein the wheel of the adjustment member is separate from the front and rear rotary agitators. 
     
     
       24. The power head of  claim 19 , wherein the adjustment member is disposed inside the housing between the front and rear rotary agitators. 
     
     
       25. The power head of  claim 19 , wherein the housing is supported on the surface by the wheel of the adjustment member and one or more of the front rotary agitator or the rear rotary agitator located within the housing. 
     
     
       26. A power head for a surface cleaning apparatus, the power head comprising:
   a housing having front and rear portions;        front and rear agitator brushes rotatably mounted in the housing;        a motor coupled to the agitator brushes for rotating the agitator brushes in opposing directions;        a handle pivotally mounted to the housing; and        a wheel disposed in the housing that rotates independent of rotation by the agitator brushes, the wheel translating pushing or pulling on the handle into pivoting of the housing relative to a surface to raise one of the front and rear agitator brushes away from the surface and lower another one of the front and rear agitator brushes toward the surface to generate a net traction force exerted by the agitator brushes on the surface that propels the housing along the surface, wherein the net traction force is in a front direction toward the front portion of the housing when the user is pushing the handle forward and the net traction force is in a rear direction toward the rear portion of the housing when the user is pulling backward on the handle.     
     
     
       27. The power head of  claim 26 , wherein the wheel is disposed in the housing between the front and rear agitator brushes. 
     
     
       28. The power head of  claim 24 , wherein the housing is an exterior housing, further comprising an inner housing rotatably mounted with the wheel in the exterior housing, the exterior housing and the inner housing pivoting about the wheel in response to the pushing or pulling of the handle. 
     
     
       29. The power head of  claim 26 , wherein the wheel is separate from the front and rear agitator brushes. 
     
     
       30. A power head for a surface cleaning apparatus, the power head comprising:
   a housing having front and rear portions;        a front rotary agitator and a rear rotary agitator rotatably mounted in the housing;        a handle pivotally coupled to the housing;        a motor interconnected with the front and rear rotary agitators for rotating the front and rear rotary agitators in opposing directions; and        an adjustment assembly coupled with the housing and defining a pivot axis of the housing between the front and rear rotary agitators, the adjustment assembly pivoting the housing about the pivot axis independent of rotation by the front and rear rotary agitators based on pushing or pulling of the handle, the front and rear rotary agitators moved relative to a surface from pivoting of the housing to generate a net traction force on the surface that propels the exterior housing along the surface, wherein the net traction force is in a forward direction when the handle is pushed toward the front portion of the housing and the net traction force is in a rearward direction when the handle is pulled toward the rear portion of the housing.     
     
     
       31. The power head of  claim 30 , wherein the adjustment assembly includes a wheel coupled with the housing that rotates independent of rotation by the front and rear rotary agitators, the housing pivoting about the wheel in response to the pushing or pulling of the handle to raise or lower one of the front or rear rotary agitators and lower another one of the front and rear rotary agitators. 
     
     
       32. The power head of  claim 30 , wherein the adjustment assembly comprises a wheel disposed in the housing that rotates independent of rotation by the front and rear rotary agitators, the housing pivoting about the wheel in response to the pushing or pulling of the handle. 
     
     
       33. The power head of  claim 30 , further comprising a lever arm interconnecting the handle with the adjustment assembly, the lever arm translating the pushing or pulling of the handle into raising or lowering at least one of the front or rear rotary agitators with respect to the surface. 
     
     
       34. The power head of  claim 30 , wherein the housing pivots about the adjustment assembly in response to the pushing or pulling of the handle, the housing pivoting to raise or lower at least one of the front or rear rotary agitators with respect to the surface. 
     
     
       35. The power head of  claim 30 , wherein relative positions of the housing, the front rotary agitator and the rear rotary agitator remain approximately constant as the housing pivots about the adjustment assembly. 
     
     
       36. The power head of  claim 30 , wherein the housing is an exterior housing, further comprising an inner housing disposed in the exterior housing and rotatably joined with the adjustment assembly, the inner housing pivoting about the pivot axis to pivot the exterior housing. 
     
     
       37. The power head of  claim 30 , wherein the adjustment assembly is separate from the front and rear rotary agitators.