Patent Application
20100088835
The present invention relates generally to the floor care equipment field and, more particularly, to a floor cleaning apparatus incorporating a drive linkage between a drive motor and rotary agitator that interrupts drive to the rotary agitator in the presence of an agitator jam.
A vacuum cleaner is an electro-mechanical appliance utilized to effect the dry removal of dust, dirt and other small debris from carpets, rugs, fabrics or other surfaces in domestic, commercial and industrial environments. In order to achieve the desired dirt and dust removal, most vacuum cleaners incorporate a rotary agitator. The rotary agitator is provided to beat dirt and debris from the nap of the carpet or rug while a pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner. The particulate laden air is then drawn into a dirt collection vessel. The air is then drawn through a filter before being directed through the motor of the suction generator to provide cooling. Finally, the air is filtered to remove any fine particles of carbon from the brushes of that motor or other dirt that might remain in the air-stream before being exhausted back into the environment.
It has long been known that the drive train and motor must be protected from damage in the event of an agitator jam whether due to a bearing seizure, a foreign object stuck between the agitator and the nozzle assembly housing, ingestion of the power cord or other event. Presently there are two main types of agitator drive systems employed in the vacuum cleaner industry: (1) belt-drive and (2) gear-drive. All such systems usually include a mechanism to prevent damage to the drive train in the event the agitator becomes jammed.
Belt-drive systems provide an inherent safeguard since the belt itself serves as an inexpensive, expendable weak-link, stretching or breaking at an overload condition and thereby preventing damage to the agitator and motor. Gear-drive systems generally rely upon an overload protector. Such a protector trips or opens a circuit to the agitator drive motor when the current drawn by that motor exceeds a pre-described threshold value anticipated to be produced during an agitator jam. A gear-drive system may, however, sustain gear-tooth fracture as the current ramps up to the threshold value that interrupts power to the drive motor.
The present invention relates to a floor cleaning apparatus equipped with a drive linkage between the agitator and agitator drive motor that incorporates a spring-loaded dog clutch that will interrupt drive to the agitator when the rotary agitator becomes jammed for any reason.
In accordance with the purposes of the current invention as described herein, a floor cleaning apparatus is provided comprising a nozzle assembly including an agitator cavity and a handle assembly pivotally connected to the nozzle assembly. A rotary agitator is carried on the nozzle assembly in the agitator cavity. A dirt collection vessel is carried on one of the nozzle assembly and the handle assembly. A drive linkage interconnects a drive motor with the rotary agitator. The drive linkage includes a ring gear having a dog clutch receiver and a dog clutch carried on the rotary agitator. The dog clutch engages the dog clutch receiver to interconnect the drive motor with the rotary agitator. In the event of an agitator jam, the dog clutch functions to interrupt drive from the drive motor to the rotary agitator thereby preventing damage to the apparatus.
More specifically describing the invention, the dog clutch includes a cam carried on a locating lug and a biaser that biases the cam into engagement with the dog clutch receiver. In one possible embodiment the biaser is a compression spring that is received around the locating lug. A cavity provided in the rotary agitator receives the locating lug and compression spring.
In one possible embodiment the drive linkage comprises a worm gear drive. More specifically a worm gear is connected to a drive shaft of the drive motor and the ring gear comprises a cooperating worm wheel connected to the agitator. A dog clutch receiver in the form of an annular series of cam receiving grooves is provided on an inner surface of the worm wheel, The drive motor is interconnected with the rotary agitator when the cam of the dog clutch is received in one of the series of cam receiving grooves. Typically the cam has a radius of curvature of between about 1 mm and about 4 mm. The compression spring has a biasing force of between about 9 N and about 34 N. The cam and the locating lug have a weight between about 0.5 g and about 2.5 g. Further each receiving groove of the dog clutch receiver has a radius of curvature of between about 1 mm and about 4 mm and a depth of between about 0.5 mm and about 2 nm, The drive linkage may include multiple dog clutches on the rotary agitator. Two of the multiple dog clutches may be provided in opposing positions.
Still further describing the invention the rotary agitator typically includes an axle, a body received over the axle and a cleaning element carried on the body. The axle is typically made of metal while the body is typically molded from plastic. The cleaning element is typically a series of bristle tufts. A bearing assembly is provided at each end of the axle to provide for free rotary movement of the agitator relative to the nozzle assembly. The ring gear may be provided on the rotary agitator adjacent one end of the axle. Alternatively, the body may include two sections and the ring gear Inlay be provided on the rotary agitator adjacent a center line of the rotary agitator between those two sections.
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:
Reference will now be made in detail to the present preferred embodiments of this invention, examples of which are illustrated in the accompanying drawings.
Reference is now made to
A pair of rear wheels (not shown) are provided on the lower portion of the handle assembly 16 and a pair of front wheels (also not shown) are provided on the nozzle assembly 14. Together these wheels support the vacuum cleaner 10 for movement across the floor. To allow for convenient storage of the vacuum cleaner 10, a foot latch (24) functions to lock the canister assembly in an upright position as shown in
In the presently illustrated embodiment, the handle assembly 16 includes a cavity adapted to receive and hold a dirt collection vessel 32. The dirt collection vessel 32 may take the form of a dirt cup 34 including a cylindrical sidewall 36, a tangentially directed inlet and an axially directed outlet. A primary filter 40 may be provided in the dirt cup 34 over the axially directed outlet. The primary filter 40 is cylindrical in shape and concentrically received within the cylindrical sidewall 36 of the dirt cup 34. Such a structural arrangement induces cyclonic airflow in the dirt cup 34 and provides for enhanced cleaning efficiency. In an alternative design, the handle assembly 16 includes a closed compartment that houses a filter or vacuum cleaner bag, of a type known in the art, which functions as the dirt collection vessel 32.
The nozzle assembly 14 includes an agitator cavity 44. A rotary agitator 46 is carried on the nozzle assembly 14 in the agitator cavity 44. A suction generator 48, including a final and a cooperating drive motor 52, is carried on the canister assembly 16. The suction generator 48 functions to generate a vacuum air stream for drawing dirt and debris from the surface to be cleaned. In one possible embodiment, the rotary agitator 46 is connected by power take off to the motor 52 of the suction generator 48. In another possible embodiment, the rotary agitator 46 is driven by a separate, dedicated agitator drive motor 52. While the suction generator 48 is illustrated as being carried on the handle assembly 16, it should be appreciated that, alternatively, it could be carried on the nozzle assembly 14 if desired.
During normal operation, the rotary agitator 46 is driven by the motor 52 of the suction generator 48 and functions to beat dirt and debris from the nap of an underlying carpet. The suction generator 48 functions to draw a vacuum air stream into the agitator cavity 44. Dirt and debris from the carpet is entrained in the air stream, which is then drawn by the suction generator 48 into the dirt cup 34, Dirt and debris is captured in the dirt cup 34 while relatively clean air is drawn through the primary filter 40. That air stream passes over the motor 52 of the suction generator 48 to provide cooling before being exhausted through a final filter, such as a HEPA filter (not shown) before being exhausted through an exhaust port 38 into the environment.
A first embodiment of the rotary agitator 46, drive motor 52 and drive linkage 54 is illustrated in detail in
More specifically describing the embodiment illustrating in
As should be further appreciated from reviewing FIGS. 2,3a and 3b, the drive linkage 54 includes a ring gear 72 in the form of a worm wheel. The ring gear 727 meshes with a worm gear 74 that is connected to the drive shaft 76 of the drive motor 52. The interface of the ring gear 72 includes a dog clutch receiver 78 comprising an annular series of cam receiving grooves 80. Typically the ring gear 72 is made from metal such as SMF 5040.
The ring gear 72 is mounted on the agitator body 58 at the centerline thereof overlying the lugs 64 that interconnect and key the two sections 62a, 62b of the body 58 together. As molded, the lugs 64 are inset relative to the outer circumference of the rest of the body 58 so as to form a channel to receive and hold the ring gear 72 in position.
The drive linkage 54 also includes a dog clutch, generally designated by reference numeral 82. The dog clutch 82 comprises a cam 84 carried on a locating lug 86. The dog clutch 82 is carried on the rotary agitator 58. More specifically, the lug 64 on the body section 62b includes a cavity 88. The locating lug 86 of the dog clutch 82 is received in this cavity 88. A biaser, in the form of a compression spring 90, is received around the locating lug 86 and held in the cavity 88.
The dog clutch 82 is typically made from a metal such as steel. The cam 84 on the dog clutch typically has a radius of curvature of between about 1 mm and about 4 mm. The compression spring 90 typically has a biasing force of between about 9 N and about 34 N. The cam 84 and locating lug 86 of the dog clutch 82 typically have a weight of between about 0.5 g and about 2.5 g. Each receiving groove 80 of the dog clutch receiver 78 typically has a radius of curvature of between about 1 mm and about 4 mm and a depth of between about 0.5 mm and about, 2 mm.
As illustrated in
In the event the agitator becomes jammed for any reason (see
An alternative embodiment of the rotary agitator 46 is illustrated in
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.
