Patent Application
20110303239
The present invention relates generally to the floor care appliance field and, more particularly, to a vacuum cleaner incorporating an agitator with an internal twin motor drive system.
A vacuum cleaner, equipped with a rotary agitator having a single internal drive motor, is disclosed in U.S. Pat. No. 7,070,636. This patent is owned by the assignee of the present invention.
By providing an agitator with an internal drive motor, one eliminates the need for a drive belt along with the inconvenient and troublesome maintenance required by such a feature. This represents a significant benefit. In addition, the overall design of the drive system is compact. Further, the internal drive system has proven to be a reliable performer characterized by a long service life.
Despite these numerous benefits and advantages, further improvements are possible. The present invention relates to an agitator with an internal twin motor drive system. Such an arrangement provides a number of additional advantages over the state of the art agitator equipped with a single internal drive motor.
Specifically, the internal twin motor drive system allows one to provide an agitator of reduced diameter with the same level or even more torque as provided by the state of the art single internal motor design. Thus, the vacuum cleaner equipped with the new internal twin motor drive system may be made with a lower profile. This allows for cleaning under lower bathroom and kitchen cabinet overhangs and furniture. Further, the twin motors may be positioned in the agitator to better balance the weight over the agitator and the overall vacuum cleaner. This functions to increase the cleaning performance and overall service life of the vacuum cleaner while providing the vacuum cleaner with neutral handling characteristics so that it is easier to steer.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved floor care apparatus is provided. That floor care apparatus comprises a housing including a nozzle assembly and a canister assembly, a suction generator carried on the housing, and a dirt collection vessel carried on the housing. An agitator cavity is provided on the nozzle assembly. A rotary agitator is provided in the agitator cavity. The rotary agitator includes an internal space. An agitator drive system is provided in the internal space of the rotary agitator. That agitator drive system includes a first drive motor and a second drive motor.
More specifically, the first and second drive motors are aligned within the internal space. The first drive motor is provided adjacent the first end of the rotary agitator while the second drive motor is provided adjacent a second end of the rotary agitator in order to provide weight balance. An air intake opening is provided at each end of the rotary agitator. An air exhaust outlet is provided between the first and second drive motors. Air filters are provided in the internal space between the intake openings and the drive motors and cooling air is drawn into these filters through the intake opening by the first and second drive motors. The cooling air flows through the first and second drive motors before being exhausted from the rotary agitator through the exhaust outlet.
In accordance with an additional aspect of the present invention, a method is provided for driving a rotary agitator in a vacuum cleaner. The method comprises providing a first agitator drive motor, providing a second agitator drive motor and simultaneously driving the rotary agitator with the first and second agitator drive motors.
More specifically, the method includes mounting both the first and second agitator drive motors in an internal space within the rotary agitator. Further, the method includes aligning the first and second agitator drive motors within the internal space while also orienting the first and second agitator drive motors in opposite directions. Thus, the method includes driving the first agitator drive motor in a clockwise direction while simultaneously driving the second agitator drive motor in a counter-clockwise direction.
Still further, the method includes the step of reducing the overall diameter of the rotary agitator. This is done by using first and second agitator drive motors to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and power output P while each of the first and second agitator drive motors has a diameter less than D and a combined power output of at least P. Thus, the resulting agitator has a reduced diameter allowing the vacuum cleaner or floor care appliance to have a lower overall profile so as to better reach under cabinet overhangs, furniture and the like. At the same time, vacuum cleaner or floor care appliance performance is in no way compromised.
In the following description there is shown and described several different embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:
a is a schematical diagram of the vacuum cleaner illustrated in
a is a detailed transverse cross-sectional view through the agitator illustrating the first power transmission assembly received in the internal space of the agitator;
b is a detailed cross sectional view of the first end of the agitator including the first drive motor and first transmission assembly; and
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
Reference is now made to
The upright vacuum cleaner 10 illustrated includes a housing 11 having a nozzle assembly 14 and a canister assembly 16. The canister assembly 16 further includes a control handle 18 and a hand grip 20. The hand grip 20 carries a control switch 22 for turning the vacuum cleaner 10 on and off. Of course, electrical power is supplied to the vacuum cleaner 10 from a standard electrical wall outlet through a cord (not shown).
At the lower portion of the canister assembly 16, rear wheels (not shown) are provided to support the weight of the vacuum cleaner 10. A second set of wheels on the nozzle assembly 14 (also not shown) allow the operator to raise and lower the nozzle assembly through selective manipulation of the height adjustment switch 24. Such a height adjustment mechanism is well known in the art. To allow for convenient storage of the vacuum cleaner 10, a foot latch 26 functions to lock the canister assembly 16 in an upright position as illustrated in
The canister assembly 16 includes a cavity 28 adapted to receive and hold the dirt collection vessel 30. In the illustrated embodiment, the cavity 28 comprises a filter bag compartment that is accessed through a removable door 32. A dirt collection vessel in the form of a replaceable filter bag 30 is received and held in that cavity. In alternative embodiments of the present invention the cavity 28 receives a dirt cup. Substantially any design of dirt cup known in the art may be provided including those designed to provide cyclonic air flow. As also known in the art, such a dirt cup may or may not include a main filter assembly.
In the illustrated embodiment, the housing 11 and, more particularly, the canister assembly 16 also carries a suction generator 36. Such a suction generator 36 comprises a suction fan and cooperating drive motor that function to generate a vacuum air stream for drawing dirt and debris from the surface to be cleaned. While the suction generator 36 is illustrated as being carried on the canister housing 16, it should be appreciated that it could likewise be carried on the nozzle assembly 14 if desired.
The nozzle assembly 14 includes an agitator cavity 38 that houses a rotary agitator 40. As best illustrated in
During operation, the scrubbing action of the bristle tufts 44 on the agitator 40 and the negative air pressure created by the suction generator 36 cooperate to brush and beat dirt and debris from the nap of a carpet being cleaned and then draw dirt and debris laden air from the agitator cavity and suction inlet 38 into the dirt collection vessel 30. Specifically, the dirt and dust-laden air passes serially through the suction inlet 38 and hose and/or integrally molded conduit in the nozzle assembly 14 and/or canister assembly 16 as is known in the art. Next, it is delivered into the dirt collection vessel/filter bag 30 which serves to trap the suspended dirt, dust and other particles inside while allowing the now clean air to pass freely through to the suction generator 36. A secondary filter (not shown) may be provided between the dirt collection vessel/filter bag 30 and the suction generator 36 in order to further insure that no particulates are ingested by the motor of the suction generator. After the air stream passes over the motor of the suction generator 36 to provide cooling, it is forced through a final filtration cartridge 48 before being returned to the environment through an exhaust port 34.
As best illustrated in
As further illustrated in
Reference is now made to
As noted above, planetary gear set carrier 84 also includes the drive ring 88 and the associated rubber drive boot 90. The drive ring 88 and rubber drive boot 90 both include a series of spaced channels 100 that receive and engage axial ribs 102 projecting inwardly radially from the inner surface of the cylindrical wall 42 of the rotary agitator 40. Thus, the rotation of the planetary gear set carrier 84 is transmitted by the drive ring 88 and associated drive boot 90 directly to and causes like rotation of the agitator 40. The rubber drive boot 90 provides the necessary damping to ensure the smooth transmission of power to the agitator 40.
The second transmission assembly 82 that transmits power from the second drive motor 54 to the agitator 40 is substantially identical to the first transmission assembly 80 and like reference numbers have been utilized to identify corresponding parts of the second transmission assembly in the drawing figures. Here it should be noted that the first drive motor 52 and first transmission assembly 80 are oriented in a first direction within the internal space 46 while the second drive motor 54 and second transmission assembly 82 are oriented in the opposite direction so that the two appear to be mirror images. Both drive motors 52, 54 simultaneously drive the rotary agitator 40 through their respective transmission assemblies 80, 82. To achieve this end the first agitator drive motor 52 is operated in a counter-clockwise direction while the second agitator drive motor 54 is operated in a clockwise direction.
It is important to provide proper cooling to the first and second drive motors 52, 54 confined within the internal space 46 in the rotary agitator 40. Toward this end, a first intake opening 110 is provided at a first end of the agitator 40 and a second intake opening 112 is provided at a second end of the agitator. A first air filter 114 is provided in the internal space 46 between the first intake opening 110 and the first drive motor 52. Similarly, a second air filter 116 is provided in the internal space 46 between the second intake opening 112 and the second drive motor 54.
A third filter 118 is provided in the internal space 46 between the first and second drive motors 52, 54. The third filter 118 covers a series of air exhaust outlets 120 provided in the wall 42 of the agitator 40. Typically the filters 114, 116 and 118 are made from open cell foam, woven filter media or non-woven filter media.
Air is drawn into the air intake openings 110, 112 and then through the first and second air filters 114, 116 by operation of the first and second drive motors 52, 54. The air is then forced past both transmission assemblies 80, 82 and the third filter 118 before being exhausted from the rotary agitator 40 through the exhaust outlets 120 (note action arrows B in
Advantageously, by using an agitator drive system 12 incorporating dual drive motors 52, 54, it is possible to reduce the overall diameter of the agitator 40 as well as the overall height of the nozzle assembly 14. The resulting “low profile” nozzle assembly 14 is capable of more easily fitting under vacuum cleaning obstacles such as furniture and bathroom and kitchen cabinets that overhand the floor so as to allow more complete and convenient cleaning. Further, this is accomplished without any loss of power P. More specifically, the overall diameter of the rotary agitator 40 is reduced by using first and second agitator drive motors 52, 54 to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and a power output (torque) P while each of the first and second agitator drive motors 52, 54 has a diameter less than D and a combined power output of at least P. For example, a state of the art vacuum cleaner uses a single internal agitator drive motor to drive the rotary agitator. That single agitator drive motor has a diameter of 46 mm requiring an agitator with an outer diameter of 56 mm. In contrast, the rotary agitator 40 of the present invention equipped with the internal dual motor drive system 12 has an overall diameter of 46 mm: that is 10 mm less than the old rotary agitator which is almost an 18% reduction in diameter. This is possible as the dual drive motors 52, 54 each have an outer diameter of only 39 mm. Specifically, since two drive motors 52, 54 are used instead of one; the drive motors themselves may be smaller thereby allowing one to produce a nozzle assembly 14 with a lower overall profile. Advantageously, this is accomplished without any loss of power.
The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.
