U.S. patent number RE42,155 [Application Number 12/340,282] was granted by the patent office on 2011-02-22 for light-weight self-propelled vacuum cleaner.
This patent grant is currently assigned to Tacony Corporation. Invention is credited to Gary Dean Ragner.
United States Patent |
RE42,155 |
Ragner |
February 22, 2011 |
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.
Inventors: |
Ragner; Gary Dean (Gainsville,
FL) |
Assignee: |
Tacony Corporation (Fenton,
MO)
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Family
ID: |
37526456 |
Appl.
No.: |
12/340,282 |
Filed: |
December 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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60403130 |
Aug 12, 2002 |
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Reissue of: |
10639659 |
Aug 12, 2003 |
07150068 |
Dec 19, 2006 |
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Current U.S.
Class: |
15/340.2;
15/384 |
Current CPC
Class: |
A47L
9/009 (20130101); A47L 5/30 (20130101); A47L
5/22 (20130101); A47L 9/0411 (20130101); A47L
9/0444 (20130101) |
Current International
Class: |
A47L
5/30 (20060101) |
Field of
Search: |
;15/319,340.2,354,355,361,369,377,41.4,43,48.2,384 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Karls; Shay L
Attorney, Agent or Firm: The Small Patent Law Group LLP
Small; Dean D. Carroll; Christopher R.
Parent Case Text
CROSS-REFERENCE TO RELATED DOCUMENTS
.Iadd.More than one reissue application has been filed for the
reissue of U.S. Pat. No. 7,150,068. The reissue applications for
U.S. Pat. No. 7,150,068 are the present application (U.S. patent
application Ser. No. 12/340,282) and U.S. patent application Ser.
No. 12/984,964..Iaddend.
This patent application claims priority from U.S. Provisional
application Ser. No. 60/403,130, filed on Aug. 12, 2002, which
claims priority from U.S. Disclosure Document No. 478,683 filed on
Aug. 17, 2000, titled, "Counter-Rotating Beater Bar Drive for a
Vacuum Cleaner".
Claims
I claim:
1. A vacuum power head for cleaning, comprising: .[.a).]. a housing
having .[.a.]. front and rear .[.portion.].
.Iadd.portions.Iaddend.; .[.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.]. .Iadd.a .Iaddend.force exerted by the hose wand on the
agitator .[.assemble.]. .Iadd.assembly.Iaddend.; .[.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 .Iadd.the .Iaddend.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.[.;.].
.Iadd.:.Iaddend. a suction fan for producing a suction airflow; a
handle; .Iadd.and.Iaddend. a dirt collection bag.[.; and.]. .Iadd.,
.Iaddend.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.[.;.]. .Iadd.:
.Iaddend.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.[.;.]. .Iadd.:
.Iaddend.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.]. .Iadd.net
.Iaddend.traction force for propelling the vacuum power head
forward and backward.
5. The vacuum power head in claim 1, wherein.[.;.]. .Iadd.:
.Iaddend.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.]. .Iadd.said front and rear
rotary agitators.Iaddend..
6. The vacuum power head in claim 5, wherein.[.;.]. .Iadd.:
.Iaddend.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.[.;.]. .Iadd.:
.Iaddend.said agitator assembly is defined by said electric motor
and said front and rear rotary agitator mounted substantially
together so .[.they.]. .Iadd.said front and rear rotary agitators
.Iaddend.are moved as a unit by said lever arm.
8. The vacuum power head in claim 1, wherein.[.;.]. .Iadd.:
.Iaddend.said lever arm is defined by a pivot arm connected to only
one rotary .[.agitator.]. .Iadd.agitators .Iaddend.and responsive
to .[.said.]. user movement to raise and lower that rotary agitator
to provide the .[.differential.]. .Iadd.net .Iaddend.traction force
for said self-propelled function.
9. The vacuum power head in claim 8, wherein.[.;.]. .Iadd.:
.Iaddend.said agitator assembly is defined by said front and rear
rotary .[.agitator.]. .Iadd.agitators .Iaddend.mounted
substantially next to each other and pivotal about an axis between
.[.them.]. .Iadd.said front and rear rotary agitators.Iaddend..
10. The vacuum power head in claim 1, wherein.[.;.]. .Iadd.:
.Iaddend.said lever arm is connected to a support roller for
raising and lowering either the front or rear .[.portion.].
.Iadd.portions .Iaddend.of the housing to provide the
.[.differential.]. .Iadd.net .Iaddend.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.].
.Iadd.portions.Iaddend.; .[.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;
.Iadd.and.Iaddend. .[.h).]. an adjustment means associated with the
lever arm and rotary agitators for adjusting .[.the.]. .Iadd.a
.Iaddend.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.]. .Iadd.a .Iaddend.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.[.;.]. .Iadd.: .Iaddend. 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.]. .Iadd.A .Iaddend.vacuum cleaner power head for
cleaning a surface, comprising: .[.a).]. a housing having .[.a.].
front and rear .[.portion.]. .Iadd.portions.Iaddend.; .[.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.]. .Iadd.a .Iaddend.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.]. .Iadd.a .Iaddend.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.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.23. The power head of claim 19, wherein the wheel of the
adjustment member is separate from the front and rear rotary
agitators..Iaddend.
.Iadd.24. The power head of claim 19, wherein the adjustment member
is disposed inside the housing between the front and rear rotary
agitators..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.27. The power head of claim 26, wherein the wheel is disposed
in the housing between the front and rear agitator
brushes..Iaddend.
.Iadd.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..Iaddend.
.Iadd.29. The power head of claim 26, wherein the wheel is separate
from the front and rear agitator brushes..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.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..Iaddend.
.Iadd.37. The power head of claim 30, wherein the adjustment
assembly is separate from the front and rear rotary
agitators..Iaddend.
Description
BACKGROUND--FIELD OF INVENTION
This invention relates to vacuum cleaners and more specifically to
vacuum cleaners with power assisted motion, or self-propelled
motion of the vacuum power head.
SUMMARY
The vacuum cleaner design disclosed .[.hear.]. .Iadd.here
.Iaddend.teaches a way to provide a self-propelled vacuum cleaner
with little or no added weight to the vacuum. Traditionally,
putting a wheel drive system on a vacuum cleaner has greatly
increased the weight of the vacuum. The need for a heavy
transmission, clutch and large drive wheels has made power assisted
or self-propelled vacuums bulky. The disclosed invention provides
very precise motion control without the need for drive wheels,
control switches, clutches, or a bulky transmission. Instead, the
disclosed invention relies on rotary brush agitator friction
(traction) to self-propel the vacuum. Most vacuums use a single
rotary brush agitator, sometimes referred to as a "beater-bar", to
agitate a carpeted surface to loosen dirt. The vacuum power head
disclosed here requires at least two rotary agitators. On the
disclosed designs the agitators rotate in opposite directions so
that dirt may be swept into the area between them by the brushing
action of the agitators. This dual agitator action is organized so
that pulling and pushing on the vacuums handle causes one or the
other rotary agitator to have greater traction than the other and
thus create a net propelling force on the vacuum's power head. When
the handle is pushed forward, more force is placed on the front
roller and thus causes it to provide greater frictional contact.
The difference between the friction .[.force.]. .Iadd.forces
.Iaddend.on the two rotary agitators determines the net force
generated. Since the bottom of the front agitator rotates from
front-to-back, greater contact force on this agitator causes a
force to be generated in the forward direction. The rotary agitator
literally drags along the floor or carpet, and pulls the vacuum
forward. When the handle of the vacuum is pulled backward the rear
rotary brush agitator is instead forced against the floor. This
causes the vacuum to be pulled backward by greater friction force
generated by the rear agitator, which is rotating in the opposite
direction of the front agitator. The control of this
self-propelling feature can be very precise if the vacuum is
balanced properly. That is, the forces on each rotary agitator
cancel when no force is placed on the vacuum handle (hose wand). If
any small force is placed on the handle, this causes the vacuum's
agitators to move the vacuum head in that direction. When the user
stops pushing, the forces on the rotary agitators automatically
adjust to bring the vacuum to a stop. Because of this moment by
moment force adjustment of the vacuum, this self-propel feature can
move the vacuum slowly or quickly depending on how fast the user
tries to move the handle. This type of vacuum or power head
attachment can be designed to be very sensitive to user applied
force. The vacuum can be thought of as a positional drive, where
the user simply moves their hand to where they want it to go and
the vacuum moves to follow the user's hand. However, if the user
moves their hand too quickly, the momentum of the vacuum can cause
a delay in the vacuum changing direction. This momentum factor
limits how fast the vacuum can react to the user. On carpeted
floors the friction forces may be quite high which can allow the
vacuum to have very fast reaction times.
BACKGROUND--DESCRIPTION OF PRIOR ART
Vacuum cleaners with counter rotating rotary brush agitators where
found in the prior art such as, U.S. Pat. No. 2,266,075 to
Replogle, U.S. Pat. No. 3,220,043 to Lampe, U.S. Pat. No. 4,426,751
to Nordeen, U.S. Pat. No. 4,850,077 to Venturini, and U.S. Pat. No.
6,073,303 to Hinojosa. Many rug shampooers exist that use counter
rotating brushes to cancel the forces generated by the scrubbing,
and provide self-propelled function without lifting and lowering
their handle, which provides a self-propelled assisted action
similar to the Applicants, but are not designed to work in the
environment of a vacuum cleaner where faster moving rotary
agitators are used and suction pressure must be compensated for.
Only U.S. Pat. No. 2,266,075 to Replogle, appears to provide a
self-propelled function that uses only the agitator bars to provide
propulsion. However, the design does not offer a way to make such a
vacuum "low profile" as seen in FIGS. 3 and 5, which is a big
advantage in today's market, nor does it describe a means for
placement of both agitators substantially next to each other for
better cleaning. U.S. Pat. No. 3,220,043 to Lampe, also shows
.Iadd.an .Iaddend.alternate contact for agitator brushes, but also
.[.have.]. .Iadd.has .Iaddend.drive wheels that make alternate
contact with the surface being cleaned. This overly complicates the
design compared to the Applicant's.Iadd...Iaddend.
OBJECTIVES AND ADVANTAGES
Accordingly, several objects and advantages of my invention are: a)
To provide a light-weight self-propelled vacuum cleaner and/or
power head attachment. b) To provide a self-propelled vacuum and/or
power head attachment without the need for drive wheels, drive
transmission or separate drive motor. Instead the vacuum uses the
rotation of the agitators to provide locomotion. c) To provide a
vacuum and/or power head with counter rotating agitators where the
agitator's contact friction force may be adjusted by the user by
sensing the force on the vacuum's or power head's handle. d) To
provide a vacuum and/or power head with counter rotating agitators
where the contact friction force is adjusted by pivoting of the
power head portion of the vacuum cleaner (see FIGS. 1 through 2B).
e) To provide a vacuum and/or power head with counter rotating
agitators where the agitator's contact friction force is adjusted
by placing a pivot point between the agitators that allow them to
rotate to different heights from a surface. This differential in
height results in one agitator being in heavier contact with the
surface and thus, creating the greatest propelling force (see FIG.
3). f) To provide a vacuum and/or power head with counter rotating
agitators where the agitators' contact friction forces are adjusted
by moving one of the agitators in the vertical direction within the
power head under the control of forces exerted on the handle of the
vacuum (see FIG. 4). g) To provide a vacuum and/or power head with
counter rotating agitators where the differential drive force
generated by the agitators may be adjusted by raising and lowering
a support wheel. The support wheel position is controlled by the
handle of the vacuum (see FIG. 5). h) To provide a vacuum and/or
power head with counter rotating agitators where the differential
drive force generated by the agitators may be adjusted by pivoting
the agitator assembly (agitators and drive motor) within the power
head portion of a vacuum cleaner (see FIGS. 3, 6A-6C).
DRAWING FIGURES
FIG. 1 Vacuum cleaner with counter-rotating agitators for
self-propelled operation. Self-propelled mode is controlled by
pivoting of the entire power head.
FIGS. 1A-C Vacuum cleaner with counter-rotating agitators shown in
stationary, forward driven, and backward driven modes.
FIGS. 2A-B Agitators and motor drive for power head in FIGS. 1, 1A,
1B and 1C.
FIG. 3 Power head design with rear mounted pivot for handle
portion. Self-propelled mode is controlled by pivoting the agitator
assembly within the power head.
FIG. 4 Power head design with handle portion mounted to a pivot
arm. Self-propelled mode is controlled by adjusting the height of
only one of the agitators with respect to the power head.
FIG. 5 Power head design with handle portion mounted to control the
height of a support roller. Self-propelled mode is achieved by
adjusting the height of the support roller to change the
proportional contact of the agitators with the surface being
cleaned.
FIGS. 6A-C Power head design with handle portion mounted to a
pivotable agitator assembly. Self-propelled mode is achieved by
pivoting the agitator assembly to change the proportional contact
of the agitators with the surface being cleaned.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The use of vacuum cleaners for cleaning floors is well known.
Vacuums are made in many different styles and types. A basic vacuum
design includes a handle portion (which normally includes a dirt
collection bag), and a vacuum power head. The power head generally
comprises a rotary agitator, an agitator motor, and a pivoting
attachment to the handle portion. This pivoting attachment
sometimes includes an air conduit for passing dust from the power
head to the collection bag. All the designs .[.show.]. .Iadd.shown
.Iaddend.here, show the air conduit built into the handle, however,
a separate air conduit may easily be used to connect the collection
bag and the power head. This would eliminate the need for the air
conduit to pass through the handle pivot joint. The suction motor
and suction fan that provide the airflow to transfer dust to the
bag can be mounted in the handle portion or in the power head
portion depending on the style of vacuum it is, or external to both
the handle portion and power head, as in a central vacuum system.
The disclosed invention deals with the power head portion of the
vacuum and how the handle portion interacts with the power head.
The suction fan and motor may be mounted within the power head or
be located completely separate from the disclosed invention (such
as when used with a central vacuum system where the suction vacuum
is usually mounted in the user's garage or with a canister vacuum).
Thus, the disclosed invention may be used on power heads with or
without suction power built into the power head itself, so that it
can be used with stand alone upright vacuums, canister vacuums,
and/or central system vacuums (see FIGS. 4, 5 and 6).
The counter-rotating agitator designs shown here can be separated
into two basic types: A) adjusting the position of both agitators
(see FIGS. 1, 3, 5 and 6), and B) adjusting the position of only
one agitator (see FIG. 4). Examples of these two types are shown in
this patent, but do not represent a complete list of possible
configurations, but some of the many possible ways the friction
(traction or drag force) on the agitators can be controlled to
provide self-propelled operation. FIGS. 1 through 2B show a vacuum
power head that adjusts the contact friction of the agitators by
pivoting the entire power head. FIG. 3 shows the agitators being
adjusted by pivoting an agitator assembly within the power head
though a linkage system. FIG. 4 shows the contact friction being
adjusted by adjusting the position of just one of the agitators.
FIG. 5 shows the contact friction being adjusted by raising and
lowering a support roller wheel. And FIG. 6 shows a power head
where a dual rotary brush agitator assembly (agitators, motor,
transmission, belts and/or gears) is pivoted inside the power head
housing to adjust the contact friction.
In FIG. 1 we see the disclosed invention designed into an upright
vacuum cleaner 30. Power head 40 comprises a housing 48, an inner
housing 49 (air channel system), a support wheel 50 and two
agitator rotors 52 and 54, each with two or more brush strips 79.
Agitator 52 is mounted in the rear and Agitator 54 in the front of
power head 40 (this front/rear positioning is .[.maintain.].
.Iadd.maintained .Iaddend.for FIGS. 1A through 2B). A fan motor and
a suction fan (neither shown) are commonly mounted on the handle
portion of the vacuum. However, power head 40 may include a vacuum
motor and a suction fan within its housing (see FIGS. 2A, 2B, 3, 4,
and 5) to provide suction air for cleaning. The vacuum motor and a
suction fan are often combined with the agitator drive motor so
that only one electric motor is needed to power everything (see
FIGS. 2A and 2B). For clarity, the drawings in FIG. 1 and FIGS. 1A
through 1C do not show the agitator motor drive assembly (seen in
FIGS. 2A and 2B). The vacuum's handle portion is attached to power
head 40 by pivot joint 46, which can rotate along an axis
perpendicular to the plane of the drawing sheet. Pivot joint 46
also allows air to flow through it from the agitators and up hose
extension 38 (hose wand). Hose extension 38 has an air outlet 36
which leads to a dirt collection bag 34. Dirt and dust 35 collects
in this bag near the bottom. Handle 32 at the top of hose extension
38 provides the user with an easy to use grip.
In FIGS. 1 through 1C, vacuum 30 has been sectioned near its
centerline to provide the shown side view. All the components have
been sectioned along this centerline except agitators 52 and 54.
For clarity, motor 60, suction fan 65, and transmission 70 have
been removed from the drawings. Exterior housing 48 and inner
housing 49 are sectioned to expose agitators 52 and 54 which are
positioned as if the entire housing was there. The agitators rotate
in opposite directions to provide better cleaning and also to
provide both forward and backward self-propelled action. The front
agitator 54 rotates clockwise (surface of agitator 54 moving
backward where it is in contact with floor surface 160) and rear
agitator 52 rotates counter-clockwise (surface of agitator 52
moving forward where it is in contact with floor surface 160) in
FIGS. 1 through 2A. In the other Figures the front and rear
agitators rotate in the same .[.directions.].
.Iadd.direction.Iaddend.. While the self-propelled vacuum head
could easily be made to operate with the agitators rotating in the
opposite directions shown, this would be undesirable because dirt
would tend to be kicked away from the center of the vacuum, and
back out onto the floor. This would happen much less with the
agitators rotating as shown in this invention. Inner housing 49
provides the air passageways for cleaning and also provides support
for the motor and suction fan (both cut away in these drawings).
Inner housing 49 may be designed to provide significant air suction
in the areas between housing 49 and the agitators, so that objects
sucked-up can move with the motion of brush strips 79. Support
wheels 50 are mounted on each side of the power head at pivot
bearing 51 to provide support for the power head and to provide a
pivot point for the power head. This pivoting action allows
differential pressure to be exerted on agitators 52 and 54 during
operation. Only the left wheel 50 is shown in shadow in FIGS. 1-1C,
since the right wheel has been cut away with the sectioning of the
housing.Iadd.. .Iaddend.The shown position of wheel 50 is for
illustration only. The wheels' actual axis of rotation may be
repositioned (mounted further forward or rearward) to provide the
desired pivoting operation. The bottom portion of the housing 48 is
designed to ride above surface 160 so that it can pivot forward and
backward as seen in FIGS. 1B and 1C respectfully.
In FIGS. 2A and 2B we see the motor assembly for the vacuum cleaner
seen in FIGS. 1-1C, (a top view in FIG. 2A, and a right side view
in FIG. 2B). Housings 48 and 49 have been removed as well as other
air conduit structures. The agitators 52 and 54 may be identical in
design with mounting bearings 78 and 76. Brush strips 79 provide a
beating action as the agitators rotate, and can comprise bristles
and/or friction ridges. Electric motor 60 drives suction fan 65 and
transmission 70. Suction fan 65 pulls air in from around agitators
52 and 54, and discharges the air through output port 63. The
airflow is directed between the agitators and the suction fan 65 by
the housings that have been removed in this drawing. Air from port
63 then flows into pivot joint 46, up handle 38 and into collection
bag 34 (see FIG. 1). While this design uses rigid joints to
transfer suction air, as we will see in later designs, a flexible
hose can be used as an interface between the power head, and the
handle and/or collection bag. Motor 60 also provides rotary power
to transmission 70 to power the agitators. Transmission 70
comprises housing 77, gears 62 and 66, and their respective drive
shafts 72 and 74, respectfully. Gear 62 and drive shaft 72 are
driven directly by motor 60. Gear 66 and drive shaft 74 are driven
by gear 62 to rotate in the opposite direction of gear 62. Thus,
shafts 72 and 74 rotate in opposite direction when motor 60 is
operating. Belt 64 is installed over shaft 72 and agitator 54 and
designed to transfer rotary power to agitator 54 in the correct
direction when the motor is operating. Belt 68 provides the same
function for agitator 52, conducting rotational force from shaft 74
to agitator 52. Bearings 76 and 78 provide the mounting points for
the agitators within housing 48. It may be desirable for bearing 76
to be better quality than bearing 78 since substantially more force
is placed on bearing 76 because of the tension in belt 64 (belt 68
for agitator 52).
In FIG. 3 we see an alternative power head design 100, where the
agitators are pivoted internally. Hose wand 102 leads to an upright
vacuum design dirt collection bag similar to bag 34, but may be
.[.connect.]. .Iadd.connected .Iaddend.to a canister vacuum or
central vacuum hose. If hose wand 102 is connected to an external
suction air supply (central, or canister vacuum), then, motor 122
needs to only drive agitators 148 and 150 and can be made smaller
than that needed power head 100. Agitators 148 and 150 can be
identical in this design and are mounted next to each other. Motor
122 is large enough to drive a suction fan 120 (behind motor 122 in
FIG. 3) and provide a suction airflow around agitators 148 and 150.
The agitator assembly comprises: two agitators 148 and 150 (though
more could be used) each having brush strips 156, bearings 152, and
gears 144 and 146 respectfully, a support bar 140 on each side, a
pivot hinge 136 on each side, an agitator connector with a rocker
pin 135, and a agitator connector 137 on each support bar 140.
Housings 110 and 112 provide covering for power head 100. Housing
112 is designed to slide along the surface to be cleaned and
provide a stable distance between the floor 160 and agitators 148
and 150. Housing 112 may also include roller wheels (not shown) to
help this sliding motion and to also move easier on hard surfaces.
Motor 122 is mounted within housings 110 and 112, and drives a
suction fan 120 and agitator 148 through shaft 114 and belt 124.
The housings provide air passageways between the agitators and
suction fan to allow dirt removal. The suction fan blows dirty air
into output port 116 which is connected to flexible hose 117. Hose
117 connects to port 119 on pivot joint 104. Pivot joint 104 is
connected to the bottom of hose wand 102 and is constrained by
connecting pin 115 which is guided within grooves on housing 110 to
be slidable in the direction of line 106. This arrangement provides
a continuous air passageway from the agitators to hose wand 102 and
ultimately to a dirt collection bag (not shown). Spring tension may
be added to pivot .Iadd.joint .Iaddend.104 to provide the proper
positioning and tension for motion 106. Pivot joint 104 pivots
around connecting pin 115 which interacts with slot 132 on control
arm 130. Pin 115 can .[.slid.]. .Iadd.slide .Iaddend.within slot
132 to rotate arm 130 about pivot bearing 134. Slot 133 is defined
on the forward end of arm 130 and interacts with pin 135, which is
connected to the agitator assembly. Movement of arm 130 thus may
adjust the orientation of the agitators. This pivoting action of
arm 130 rotates the agitator assembly around pivot bearing 136 on
support bars 140 in response to force placed on hose 102 by the
user. The entire agitator assembly is attached to both sides of the
housing at pivot hinge 136, which allows the assembly to rotate as
shown by the small arrows 142. Support bars 140 on each end of the
agitators.[.,.]. connect the agitators 148 and 150 together by
their rotary bearings 152. Support bars 140 attach directly to the
agitator bearings 152 to allow the agitators to rotate between
them. Gears 144 and 146 attached to rotary agitators 148 and 150
respectfully and meshing so that power is transmitted from agitator
148 to agitator 150 and so that the agitators rotate in opposite
directions. Brush strips 156 on each agitator helps cleaning by
agitating surface 160 to loosen dirt. The agitator assembly is
designed for substantially stationary operation with pivot hinge
136 positioned substantially in-line with rocker pin 135 and drive
motor shaft 114. This in-line condition is the natural state for
the assembly with tension from belt 124 pulling them in-line. This
in-line arrangement reduces the amount of force needed to overcome
belt tension when rotating the agitator assembly in either
direction.
Power head 100 in FIG. 3 can be modified so that pivot joint 104
connects directly to rocker arm 130 at pin 115. Pin 115 would pivot
in a bearing joint which would replace slot 132, and guides in
housing 110 would be designed to allow pivot joint 104 to move
along direction arrows 106a. This arrangement still allows force
from hose wand 102 along direction arrows 106 to rotate pivot bar
130 around pivot bearing 134 and thus pivot the agitator assembly.
Note that housing 112 will need to be modified slightly to make
room for this new vertical motion of pivot joint 104.
In FIG. 4 we see an alternative design where one adjustable
agitator 52 is used to adjust the self-propelled function for power
head .[.160.]. .Iadd.170.Iaddend.. Power head .[.160.]. .Iadd.170
.Iaddend.is attached to a pivot joint 164 and suction hose wand (or
hose wand) 162 similar to other handle portions seen this patent.
This design shows a power head for use with canister vacuums,
central vacuum systems and the like without an onboard vacuum fan,
however the design can easily add a larger drive motor with a
suction fan to provide its own vacuum air supply. Agitator drive
motor 190 is shown in phantom lines, and drives rotary agitators 52
and 54 through belts or gears similar to the method shown in FIGS.
2A through 3. The same agitators 52 and 54 can be identical and are
used here to point out how industry presently uses a number of
standard agitator designs that are interchangeable between many
different vacuum cleaners. Housing 170 is designed to provide air
passageways so that air can flow from the agitators along lines
167a and 167b to flexible hose 168 along line 167c and eventually
to suction hose 162 along line 167d. Flexible hose 168 allows pivot
joint 164 to move along line 166 and still provide a clear air
passageway from the power head to suction hose 162. The movement of
pivot joint 164 is controlled by a pair of pivot arms 180 (only
left side shown in shadow behind pivot joint, right side pivot arm
cut away in section). Pivot arm 180 pivotally attaches to joint 164
at pivot bearing 182. Pivot arm 180 is mounted to the housing at
pivot bearing 184, and connects agitator 52 to it at pivot bearing
186. Thus, suction hose 162 when moved, causes agitator 52 to raise
and lower within housing 170. Arm 180 may move to alternate
positions (see example position 180a) where agitator pivot position
186a is lowered toward surface 160 to force agitator 52 onto the
surface at alternate position 52a of agitator 52. Support roller
172 pivots on bearing 178 and is positioned near the rear agitator
52 so that when agitator 52 is lifted from surface 160 agitator 54
remains in contact with the surface. Pivot bearing 178 is
positioned so that forces exerted down suction hose 162 (user
pushing forward) are directed in front of bearing 178 so agitator
54 is kept in contact with surface 160 to provide forward
propulsion. Agitator 54 may be mounted in a fixed location on the
housing or may be spring loaded to provide a more constant downward
force on the surface. Arm 180 may also be pre-loaded with a spring
(not shown) to compensate for the weight of the suction hose 162
and pivot joint 164 so that little or no force is needed on the
handle to hold power head 160 in one position during use. In
general, there is not much need for spring loading if pivot 182 is
place directly above hinge 184, when agitator 52 is positioned for
stationary operation. In this way, the weight of the suction hose
is supported by hinge 184 and produces very little torque on arm
180. Some spring tension may be added to counteract the force
exerted by agitator 52 on arm 180 (equal downward force is needed
on agitators 52 and 54 to balance traction forces against surface
160). Landing surface 173 on housing 170 provides support for the
housing when agitator 52 is raised.
In FIG. 5 we see an alternative power head design 200. This design
shows a power head for use with canister vacuums, central vacuum
systems and the like without an onboard vacuum fan, however the
design can easily add a larger drive motor with a suction fan to
provide its own vacuum air supply. Movable support roller wheels
214 on each side of the power head are used to adjust the contact
force of agitators 52 and 54 with respect to surface 160. For this
design agitators 52 and 54 and drive motor 190 are attached
directly to housing 202. Roller wheels 210 on each side of the
power head (right side cut away) helps support the agitators and
also provide a pivot axis for the agitators and housing 202. Motor
190 may be connected to a suction fan to provide suction within
power head 200 if desired. If a suction fan is driven by motor 190,
generally more power will be need than if the motor rotates just
the agitators. The agitators are mechanically connected to drive
motor 190 similarly to the design in FIGS. 2A and 2B. Gears and
other power transfer systems may also be used to transmit power
from the motor to the agitators. The method of transferring power
to the agitators is not important to this invention. In fact, the
agitators may have a motor built directly into it so that no power
transfer system is needed at all, as is done in some vacuums. A
continuous air channel is formed by housing 202, channel 204,
flexible hose 206, pivot joint 164 and suction hose 162, leading
from the agitators to the exit on suction hose 162. Pivot arms 220
(only left arm shown, right arm cut away) attaches pivot joint 164
at pivot pin 183, to housing 202 at pivot bearing 226. Arm 220 also
attaches to support roller 214 to housing 202, which is movable in
response to movement of suction hose 162 which is attached to arm
220. Arm 220 provides a leverage advantage to roller 214 so that
the rear portion of housing 202 may be raised by pushing suction
hose 162 forward (magnitude of movement of roller 214 is
exaggerated for clarity).
In FIG. 5, roller position 214a shows an alternate position for
roller 214 which would raise agitator 52 off surface 160 and
simultaneously force agitator 54 against surface 160. The drawing
shows wheel position 214a below surface 160 for the motion of lever
arm 220, this is to simplify the drawing since showing housing 202
and all the components within it in an alternate raised position
would make the drawing messy to read. Spring tension may be added
to lever arm 220 to provide the proper tension during operation,
and provide little or no force needed on hose 162 to hold the
vacuum stationary during operation.
In FIGS. 6A through 6C we see an alternative power head design 240.
In this design, housing 242 is designed to glide along floor
surface 160. Surfaces 244, 246, and 248 provide a relatively flat
sliding surface for the housing. Rollers may also be added on any
these bottom surfaces to assist in the movement of the housing
along floor surface 160. Within housing 242 .[.a.]. .Iadd.an
.Iaddend.agitator assembly is pivotally mounted to the housing at
pivot pin 258. The agitator assembly comprises agitators 52 and 54,
support structure 256 on both sides, connecting support 254, hinge
connector 252, and the powered equipment (motor, fan and
transmission not shown in FIG. 6, but may be similar to that in
FIGS. 2A-B) to rotate the agitators in opposite directions as shown
by the arrows on the agitators. Pivot hinge 46 is positioned so
that user force coming straight down hose 38 passes in front of
pivot hinge 258 (repeating: the projected line of force parallel to
hose 38 passes in front of pivot hinge 258). This positioning
causes the agitator assembly to pivot forward (clockwise) when the
user pushes forward on suction hose 38 (handle) and pivot backward
(counter-clockwise) when the user pulls backward on suction hose
38. The proper positioning of pivot joints 46 and 258, thus, allows
a pivoting action of the agitator assembly .[.withing.].
.Iadd.within .Iaddend.housing 242. This pivoting can generate a
differential traction from agitators 52 and 54. This difference in
downward force on the two agitators with respect to surface 160
causes a difference in traction between the two agitators, which
provides a net forward or backward force to self-propelled the
power head. While the drawings in FIGS. 6A-C show one method of
linking the forces exerted by suction hose 38 to pivot the agitator
assembly there are many ways this can be done. For example, if the
connection point of pivot joint 46 is desired to be placed near the
rear of power head 240 (near agitator 52) this may be done with a
simple lever arm similar to those seen in FIGS. 3, 4, and 5. The
pivoting of the agitator assembly would then be accomplished by
leveraging some point on the assembly to pivot it in the proper
direction. For example, if one wanted to specifically leverage the
assembly near rear agitator 52 then a lever arm similar to arm 130
in FIG. 3, though much shorter and with the pivot point for the
lever arm located between pivot joint 46 and its connection to the
assembly. Numerous other ways exist for mechanically providing the
actuation of the agitator assembly to produce propulsion.
Operational Description--FIGS. 1 through 6C
The operation of all the designs disclosed here centers around
providing control over the differential traction between two
counter-rotating agitators. By providing the proper control over
this differential traction one can use it to propel (self-propel)
the vacuum or power head in the direction the user pushes. The
user's force exerted on the design is amplified by the sensitivity
of agitator brushes to the contract pressure exerted on them. Thus,
a small user force linked to one of the agitators can generate
significant traction on carpets so that the agitator easily propels
the vacuum. While all the vacuums/power head examples disclosed
here produce their self-propulsion from the counter-rotating
agitators, the specifics of how they control the differential
traction is different. The control of the agitators can be
separated into two basic types: A) those that adjust both
counter-rotating agitators (see FIGS. 1, 3, 5, 6), and B) those
that adjust one of the counter rotating agitators (see FIGS.
4--note that agitator 54 is still slightly effected by forces
exerted on hose wand 162). The adjustment of both agitators has an
advantage over the single agitator adjustment because when one
agitator is increasing traction force, the other agitator can be
decreasing traction force so that a greater net traction force can
be generated. In the following section the operation of specific
examples will be discussed.
The vacuum in FIGS. 1 through 1C has the simplest construction of
all the designs presented here. Power head 40 operates as a single
unit, with its components remaining fixed with respect to each
other during operation. Roller wheels 50 .[.is.]. .Iadd.are
.Iaddend.designed to support most of the downward force created by
power head 40. Suction air flowing around agitators 52 and 54 may
cause housing 48 to pulled down onto surface 160 with considerable
force. Steps can be taken to reduce the vacuum suction under the
housing, but some vacuum suction is needed for the power head to
clean properly. Thus, wheels 50 should be places relatively near
the "center of pressure" on the housing so that agitators 52 and 54
experience approximately even force pressing them onto surface 160
(when the user is not pushing or pulling on handle 32). In FIG. 1A,
during operation with power head 40 in a stationary position, the
vacuum needs very little force on the handle to hold it in place.
Agitators 52 and 54 are both striking surface 160 with
approximately the same downward force and generating approximately
the same traction force away from each other so that they cancel
each other out. The traction force on the agitators can be quite
large in this stationary operation, but the agitator's
counter-rotating design substantially equal and opposite traction
forces so that they cancel (see FIG. 1A).
In FIG. 1B we see the same vacuum power head 40 with the user
pressing lightly forward with force 41a on handle 32 (see FIG. 1).
This small force 41a, directed down suction hose 38, causes housing
48 to experience a forward pivoting force around bearing 51. Pivot
joint 46 is located above wheel 50 so that force 41a produces a
clockwise torque around pivot bearing 51. At the same time, the
contact force of agitator 54 onto surface 160 increases and the
contact force on agitator 52 decreases. This creates an imbalance
of traction forces on the agitators, and a net forward directed
force 41b is generated which propels the power head forward.
When the user pulls backward on the handle, as seen in FIG. 1C, the
power head pivots backward around bearing 51. Again the location of
pivot joint 46 allows force 43a to create a counter-clockwise
torque around pivot bearing 51. This torque is used to force
agitator 52 against surface 160 to generate traction, while at the
same time, agitator 54 is raised, thus reducing its traction. The
result is a net backward directed force 43b, which propels the
power head backward.
Many things can be adjusted on power head 40 to provide optimized
operation for specific uses. For example, the location and size of
support wheel 50 may be modified to work best with the location of
pivot joint 46. Support wheel 50 may also be placed in a different
location to compensate for asymmetric suction air force on the
housing. And of course, many different methods of linking the user
applied force to create differential contact force for the
agitators. Some of these methods are shown in FIGS. 3 through 6.
Many other methods also exist, specifically the front and rear
agitators can rotate in reversed directions and still operate (with
modified control linkage) since it is the opposed rotating
agitators that allows it to produce a differential force in either
direction (forward and backward). Thus, as long as the two
agitators are rotated in opposite directions, applied force from
the hose wand can be used to adjust the agitator(s) to generate the
properly directed net traction force.
The reader should note that the operation of these types of
self-propelled assisted vacuum is not .[.a.]. .Iadd.an
.Iaddend.on/off type of propulsion. Instead, the amount of
self-propulsion is directly related to the amount of force the user
puts on the vacuum handle. The rotating agitators amplify the user
applied force, and through proper geometry of its components,
.[.amplifies.]. .Iadd.amplify .Iaddend.it to propel the vacuum in
the direction of the user applied force. Thus, power head 40 moves
with the user, responding slowly if the user moves slowly and
quickly if the user moves quickly.
In FIGS. 2A and 2B we see the motor drive system within power head
40. During operation motor 60 turns both agitators 52 and 54, and
suction fan 65. Suction Fan 65 may be driven directly by motor 60.
Agitators 52 and 54 are driven by power transfer from motor 60
through transmission 70 and drive shafts 74 and 72, and then by
belts 68 and 64 respectfully. Gear 62 is directly powered by the
motor, and gear 66 is driven by gear 62 in the opposite direction.
This provides power output to shafts 72 and 74 which turn in
opposite directions. While cleaning, air is sucked from around
agitators 52 and 54 and pulled through suction fan 65. This dirty
air is then discharged through output port 63 for transport to the
collection bag. Air from port 63 travels to pivot joint 46, up
through air channel 42 in suction hose 38, through outlet 36 and
into dirt collection bag 34, where the air is filtered of its dirt
and cleaned air passes through the walls of the bag. Of course,
other dirt collection containers and separators can be used, such
as, bag-less or cyclone type systems.
In FIG. 3 we see an alternative design for power head 100 for a
vacuum cleaner. Power head 100 may include a suction fan 120 driven
by electric motor 122 in which case no external air suction source
is needed. If motor 122 only powers the rotary brush agitators 148
and 150 then an external air suction source will need to be
connected to suction hose 102. However, the placement of the
suction fan does not .[.effect.]. .Iadd.affect .Iaddend.the essence
of the disclosed invention, which involves the use of
counter-rotating rotary agitators to self-propel the power head,
and is only mentioned here for clarity and completeness. For this
design, suction fan 120 provides vacuum airflow from the agitator
area along airflow path 107a. Airflow along path 107a then passes
through suction fan 120 and out through channel 116, flexible hose
117, and pivot joint 104 along airflow path 107b. Finally, the
airflow continues out through hose wand 102 along airflow path
107c.
During operation of power head 100, motor 122 turns shaft 114 which
moves belt 124, which turns rotary agitator 148. Gear 144 on
agitator 148 interacts with gear 146 connected to agitator 150, to
turn agitator 150 at approximately the same rate as agitator 148.
When no force is placed on hose wand 102, the linkage between pivot
peg 115 and the agitators is designed to position the agitators so
that their traction forces substantially cancel. When the user puts
a small force on wand 102, pivot joint 104 may move in and out as
shown by arrows 106 (or 106a in modified version). When pivot joint
104 moves, peg 115 interacts with slot 132 and pivots lever arm 130
around pivot bearing 134. The mechanical advantage of lever arm 130
allows a small force at peg 115 to produce a much larger force at
pivot peg 135. This causes the agitator assembly (agitators 148 and
150, support 140, hinge bearings 136, and pivot peg 135) to rotate
about hinge bearings 136 as shown by arrows 142. This
rotation.[.,.]. causes one agitator to move into greater contact
with surface 160 as the other agitator moves into less contact with
surface 160, and thus, provides self-propulsion. For example, in
FIG. 3, pushing hose 102 forward forces peg 115 downward to rotate
lever arm counter-clockwise about bearing 134. This causes slot 133
to lift up on peg 135 raising agitator 148 away from surface 160,
while at the same time lowering agitator 150 into greater contact
with surface 160. This creates a difference in traction force
between the two agitators and their traction forces no longer
cancel. The greater contact force of agitator 150 causes a greater
traction force so that there is a net force to propel power head
100 forward. When the user pulls backward on hose 102, lever arm
130 rotates in the opposite direction and agitator 148 is lowered
and agitator 150 is raised away from surface 160. Thus, the
traction on agitator 148 is greatest and the power head is
propelled backward. For the design shown in FIG. 3, housing section
112 provides a low friction surface that slides easily against
surface 160. Generally, rollers (wheels) would be included on the
bottom of power head 100 to reduce sliding friction, such rollers
are not shown here to keep the drawing readable, but is a common
practice in the art of vacuum head design. The less sliding
friction that exists on power head 100 the better the differential
traction from agitators 148 and 150 can propel the vacuum (upright
vacuum, power head, or power wand).
In FIG. 4 we see another alternative dual-agitator vacuum head
where the agitator's traction (friction) with surface 160 may be
individually controlled. In this design, agitator 54 is stationary
with respect to housing 170, while agitator 52 is movable. During
operation pivot joint 164 and hose 162 can rotate lever arm 180
about its axis bearing 184. Lever arm 180 is designed so that
agitator 52 is raised when hose 162 is pushed forward and lowered
when hose 162 is pulled backward. Thus, when the user pushes
forward on hose 162, agitator 52 is lifted away from surface 160
and the force from the user tends to rotate housing 170 forward and
press agitator 54 onto surface 160. The position of roller wheel
172 provides the axis for this rotation. This results in an added
traction force on agitator 54 that helps propel power head 160
forward for the user. When hose 162 is pulled backward, lever arm
180 rotates to force agitator 52 into surface 160. This creates
traction for agitator 52 while the backward force on hose 162 tends
to lift agitator 54 away from surface 160. The result is a net
traction force propelling power head .[.160.]. .Iadd.170
.Iaddend.backward with the user's pulling.
The design in FIG. 4 may be adjusted in many ways to provide
optimum operation. For example, by moving wheels 172 and the
position of agitators 52 and 54 with respect to each other, better
traction control may be .[.achieve.]. .Iadd.achieved.Iaddend.. If
wheel 172 is moved forward so that its axle 178 is substantially
in-line with the direction of applied force down hose wand 162,
then pushing and pulling on the hose wand by the user will have
very little effect on the contact force of agitator 54 on surface
160. Thus, agitator 54 would have a relatively constant traction
force, and raising and lowering agitator 52 would be used to adjust
the net traction force, either forward or backward respectfully by
adjusting the traction force on agitator 52 alone. Arm 180
amplifies the force exerted by the hose wand on agitator 52 so that
very little force need be exerted on hose wand 162 to adjust the
position of agitator 52. Also, the lever arm need not control the
rear agitator, but may instead control the front agitator 54.
Controlling the front agitator may provide many advantages for some
designs. Also additional roller wheels may be added to assist the
control over traction of the agitators. For example, another roller
wheel pair may be attached to the housing in front of agitator 54.
This provides a second pivot point for the housing which can help
with backward propulsion. When hose 162 is pulled backward
(lowering agitator 52) the rear portion of housing 170 is raised.
If an additional wheel set is in front of agitator 54 then this
rotation will tend to lift agitator 54 away from surface 160 by
rotating about this new wheel set. Many other possible
configurations are also possible.
In FIG. 5 we see another alternative dual-agitator vacuum head
where the agitator's traction (friction) with surface 160 is
controlled by a movable roller wheel 214. Wheel 214 moves in the
vertical direction in response to movement of lever arm 220. Lever
arm 220 is controlled by movement in hose 162 and pivot joint 164
through pivot pin 183. During operation, when the vacuum is held
stationary, agitators 52 and 54 just make contact with surface 160
and produce approximately the same traction force so that no net
propulsion force exists. Arm 220 amplifies the force exerted by the
hose wand on wheel 214 so that very little force need be exerted on
hose wand 162 to adjust the agitators' positions. As hose wand 162
is pushed forward, lever arm 220 rotates and forces wheel 214
against surface 160 and lifts-up the rear portion of housing 202.
This tends to rotate power head 200 around support wheel 210. Since
the agitators in this design are attached directly to the housing
they pivot with the power head. This results in agitator 54 being
pressed into surface 160 and agitator 52 being lifted away from
surface 160. This generates a traction force differential between
the two agitators and a net force is created that propels the power
head forward in the direction of the user's applied force. When
hose wand 162 is pulled backward, wheel 214 is lifted off of
surface 160. This causes the power head to be supported only by
wheel 210 and agitators 52 and 54. Housing 202 can be designed so
that greater vacuum pressure force exists rearward of wheel 210
than forward of wheel 210 (though more airflow may be on the
forward end). This means that once wheel 214 is lifted from surface
160 the power head tends to rotate counter-clockwise because of the
greater downward suction on the rear half of the power head. This
rotates the housing backward and forces agitator 52 into surface
160 while at the same time lifting agitator 54 away from surface
160. This causes the rear portion of housing 202 to lower itself
nearer surface 160. While pulling backward on lever pin 183 notice
that a portion of that force is trying to lift-up on the rear
portion of housing 202. This upward force is easily countered by
the large forces that may be generated by vacuum suction under
housing 202. Thus, the area rearward of wheel 210 need only be
slightly larger than the area forward of wheel 210 for the suction
force to be significantly greater rearward of support wheel 210
than in front of it. This means agitator 52 will be pressed
strongly against surface 160 even when hose wand 162 is pulled
upward on strongly. Notice that the natural tendency of this design
is to lift the housing on the side opposite the desired direction
of motion. That is, when moving backward, the front of housing 202
is lifted. This reduces vacuum pressure on that side of the vacuum
because of the larger airspace between surface 160 and the housing.
Thus, the design in FIG. 5 tends to generate greater suction force
downward for housing 202 on the portion that needs it (correct
agitator forced against surface 160). Additional skirting (not
shown) may also be added around this design to provide a consistent
vacuum seal around housing 202. This skirting could make the vacuum
pressure forces more consistent while power head 200 is pivoted
about wheel 210. Also note that this control arrangement will work
with the two agitators much closer together, such as, both near the
front as in FIG. 3. Pivoting of the body will still tend to create
a traction difference between the agitators.
In FIG. 6 we see another alternative dual-agitator vacuum head
where the agitator's traction (friction) with surface 160 is
controlled by a pivotable agitator assembly 250. For this design,
housing 242 is in contact with surface 160 and supports then entire
power head 240. Housing 242 supports the power head on sliding
surfaces 244 and 246 which may include roller wheels or other
friction reducing structures. Housing 242 also controls the amount
of air bled under the housing so that the vacuum pressure is
somewhat controlled. This helps maintain a consistent vacuum force
downward on the housing. During operation, agitators 52 and 54
rotate in opposite directions and produce approximately equal and
opposite traction forces when no force (no force on hose wand 38)
is applied by the user (see FIG. 6A). When the user presses forward
(force 243a) on hose wand handle 38, agitator assembly 250 rotates
forward as seen in FIG. 6B. This rotation presses agitator 54 into
surface 160 while at the same time lifting agitator 52 away from
the surface. The result is a net force 243b, generated by the
agitators against surface 160, to propel power head 240 forward.
Similarly, when the user pulls back (force 253a) on hose wand
handle 38 (see FIG. 6C), the agitator assembly rotates
counter-clockwise. This forces agitator 52 against surface 160 and
lifts agitator 54. The resulting net force 253b propels the power
head backward. Support structures 252, 254, and 256 on agitator
assembly 250 acts like a lever arm to pivot the agitators into, and
away from, surface 160. This lever arm action may be modified by
adjusting the positions of pivot bearing 258 and pivot joint 46.
Additional linkages can also be included to allow pivot joint to be
located anywhere on housing 242. Also, the location of agitators 52
and 54 may be modified. In general, the closer together agitators
52 and 54 are placed to one another the greater the leverage
created to generate a differential force against surface 160. Thus,
if both agitators 52 and 54 where placed side by side near the
center of housing 242 a very small force on pivot joint 46 would
create a large difference in contact forces for the agitators. This
in turn would generate a large net traction force to propel the
power head.
Ramifications, and Scope
The disclosed self-propelled power head solves several long
standing problems for the vacuum cleaner industry, such as,
allowing a light-weight self-propelled vacuum to provide better
cleaning with two counter rotating agitators, providing exact
self-propelled motion control in a light-weight system, and
providing assisted self-propelled motion without heavy
transmissions, clutches or electronic controls.
Although the above description of the invention contains many
specifications, these should not be viewed as limiting the scope of
the invention. Instead, the above description should be considered
illustrations of some of the presently preferred embodiments of
this invention. For example, while all the designs shown in this
patent use mechanical linkages to control the differential pressure
on the agitators, this need not be the only way it is done. For
example, each of the designs in FIGS. 3, 4, 5, and 6A-C can be
controlled by an electric actuator, solenoid, positioning motor, or
other similar control device. Instead of mechanical linkages, a
sensor in the vacuum's handle may sense the direction the user is
pushing and move the agitator assembly (FIGS. 3 and 6A-C), single
agitator (FIG. 4), control rollers (FIG. 5), or other means to
adjusting the position and forces on the agitators. This electronic
type of control can allow more choice as to how the agitators are
controlled. For example, the front agitator may be adjusted by an
electric actuator. Normally the front agitator is difficult to get
to because of the drive system and because the handle portion is
usually attached near the back of the power head to allow the
handle to lay flat when going under furniture. Finally, many
aspects of the designs may be adjusted to fine tune the performance
of the system. For example, the agitator drive system may be
designed to produce greater torque than standard vacuums for the
specific purpose of accelerating the power head (vacuum cleaner)
more quickly, and/or to keep the agitators from bogging down on the
surface being cleaned. Many other adjustments to the support roller
positions and size, and the location of all the power head's
components may be moved to different locations depending on the
desired needs of the user (i.e. low profile to get under furniture,
etc.). Springs and other tensioning devices can be used in many
ways to provide balanced traction force on the agitators. For
example, in FIG. 3 if motor 122 and fan 120 pivot with agitators
148 and 150 then tensioning springs can be used to help support the
weight of motor 122, fan 120 and hose wand 102, so that agitator
friction forces are nearly balanced when the user applies no force
to the handle of hose wand 102. Finally, the five different ways of
controlling rotary agitator traction are shown in FIGS. 1 through
6. These methods may be mixed and matched or combine with other
designs to create new ways for producing the desired control over
the vacuum's self-propelled assist feature.
Thus, the scope of this invention should not be limited to the
above examples but should be determined from the following
claims.
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