Vacuum cleaner base with nozzle height adjustment

An upright vacuum cleaner comprises a base assembly pivotally connected to an upright assembly. The base assembly comprises housing, a support, and a ratchet-operated nozzle height adjustment mechanism for raising or lowering a suction nozzle on the base assembly relative to a surface to be cleaned. The ratchet-operated nozzle height adjustment mechanism includes a ratchet mechanism for raising and lowering the housing relative to the support.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to suction cleaners, and in particular, to adjusting the vertical position of a suction nozzle of the base portion of a vacuum cleaner.

2. Description of the Related Art

Upright vacuum cleaners employing cyclone separators are well known. Some cyclone separators follow textbook examples using frusto-conical shape separators and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Typically, working air enters and exits at an upper portion of the cyclone separator as the bottom portion of the cyclone separator is used to collect debris. Furthermore, in an effort to reduce weight, the motor/fan assembly that creates the working air flow is typically placed at the bottom of the handle, below the cyclone separator.

BISSELL Homecare, Inc. presently manufactures and sells in the United States an upright vacuum cleaner that has a cyclone separator and a dirt cup. A horizontal plate separates the cyclone separator from the dirt cup. The air flowing through the cyclone separator passes through an annular cylindrical cage with baffles and through a cylindrical filter before exiting the cyclone separator at the upper end thereof. The dirt cup and the cyclone separator are further disclosed in the U.S. Pat. No. 6,810,557 which is incorporated herein by reference in its entirety.

U.S. Pat. No. 4,571,772 to Dyson discloses an upright vacuum cleaner employing a two stage cyclone separator. The first stage is a single separator wherein the outlet of the single separator is in series with an inlet to a second stage frusto-conical separator.

SUMMARY OF THE INVENTION

According to one embodiment of the invention, a vacuum cleaner comprises a base assembly having a housing, a suction nozzle, a pair of wheels at a rear portion of the housing, a support at a front portion of the housing, and an adjuster between the housing and the support to selectively adjust the vertical position of the suction nozzle with respect to a surface to be cleaned. The adjuster comprises a ratchet mechanism movably mounted between the support and the housing for movement between a raised and a lowered position, wherein the ratchet mechanism is shaped to raise the housing with respect to the support in the raised position and to lower the housing with respect to the support in the lowered position, and a first actuation rod. A foot pedal is mounted to the housing and incrementally moves the ratchet mechanism between the raised and lowered positions.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An exemplary upright vacuum cleaner10according to the invention is shown inFIGS. 1-3, and comprises an upright assembly12pivotally mounted to a base assembly14. The upright assembly14further comprises a primary support section16with a grip18on one end to facilitate movement by the user. A motor cavity20is formed at an opposite end of the upright assembly12and contains a commonly known motor/fan assembly22(FIG. 17) oriented transversely therein. The upright assembly12pivots relative to the base assembly14through an axis formed relative to a shaft24(FIG. 9) within the motor/fan assembly. The upright assembly12further receives a dirt separation and collection assembly, illustrated as a cyclone separation assembly26on the primary support section16. The cyclone module assembly26forms part of a working air path fluidly connecting the base assembly14to the motor/fan assembly and separates and collects debris from a working air stream for disposal after the cleaning operation is complete. The details of cyclone separators are known in the vacuum cleaner art and will not be described in detail herein.

The base assembly14further comprises a lower housing28that mates with an upper housing30to form a brush chamber32in a forward portion thereon. A rotating brush roll assembly34is positioned within the brush chamber32. A pair of rear wheels36is secured to a rearward portion of the base assembly14, rearward being defined relative to the brush chamber32. A variety of different base assembly14configurations can be assembled to the upright assembly12that comprise various features. Typically, the base assembly14can vary in width so that the cleaning path can be narrower or wider depending upon the size of the brush chamber32. A suction nozzle38is formed at a lower surface of the brush chamber32on the base assembly14and is in fluid communication with the surface to be cleaned. A foot conduit40provides an air path from the suction nozzle38through the base assembly14and terminates in a hose grip receiver42. In the preferred embodiment, the foot conduit40is a smooth rigid blow molded tube with a bendable portion44that coincides with the pivot point between the base assembly14and the upright assembly12to allow the upright assembly12to pivot with respect to the base assembly14. In an alternate embodiment, the foot conduit40is a commonly known flexible hose typically used in the vacuum cleaner industry. In yet another embodiment, the air path is formed by and between the housings28,30with no secondary blow molded or flexible hose parts.

A live hose46terminates in a fixed hose grip48on one end and a cyclone inlet receiver50on the other end. The live hose46is preferably a commonly known flexible vacuum hose. The cyclone inlet receiver50is rigidly fixed to an upper portion of the primary support section16of the upright assembly12. The hose grip48is removably received in the hose grip receiver42via a bayonet latch or, alternatively a friction fit so as to create an air tight seal when the hose grip48is inserted therein. The live hose46is managed via a pair of commonly known hose hooks (not shown) at a lower portion of the primary support section16and near the grip18as is commonly known in the vacuum industry.

A cyclone outlet receiver52is integrally formed on an upper portion of the primary support section16in close proximity to the cyclone inlet receiver50and is in fluid communication with a pre-motor filter assembly54positioned upstream of an inlet to the motor/fan assembly22located in the motor cavity20. Fluid communication can be accomplished by an air path (not shown) integrally formed in the primary support section16or can be a rigid blow molded tube or a commonly known flexible vacuum hose. An outlet of the motor/fan assembly22is in fluid communication with a working air exhaust assembly56. The working air exhaust assembly56is positioned adjacent to or may be integral with the primary support section16, in fluid communication with the exhaust air flow from the motor/fan assembly22. A variety of commonly known filter elements (not shown) can be utilized in the exhaust assembly56. In the preferred embodiment, the filter is a commonly known high efficiency particle arrestor (HEPA) filter element.

Referring toFIG. 4, the lower housing28further comprises the suction nozzle38at a forward end and a handle pivot cavity116centrally located on a rearward end relative to the forward end. A plurality of upright retaining tabs118are oriented generally orthogonal to the lower housing28and on either side of the handle pivot cavity116, and a pair of retaining tabs120are positioned on the side edges of the lower housing28. A pair of wheel bearings122is formed on a side rear edge of the lower housing28and fixedly receives a wheel axle124upon which the wheel36freely rotates. The wheel36is captured by a flange126on one end of the axle124. Referring toFIG. 5, the axle124is secured in the lower housing28via an integrally formed coaxial snap feature comprising a pair of integrally formed resilient engagement members125offset axially from the axle124. The engagement members125are tapered relative to the axle124shaft to provide a lead in that is self-centering when being inserted into the corresponding wheel bearing122. In the preferred embodiment, the wheel36load is centered longitudinally on the axle124so that bending moments on the axle124are minimized. Lower bending loads enable the use of smaller diameter axles, which, in the preferred embodiment, are made of a plastic with adequate lubricity. A suitable plastic material is sold by DuPont under the trade name Delrin®. This axle design significantly reduces costs over metal axles that are typically found in vacuum cleaners.

Referring back toFIG. 4, the upper housing30further comprises a handle cut out134to accommodate rotation of the upright assembly12about the motor cavity20. A plurality of retaining surfaces132are formed by apertures in an upper surface of the upper housing30that correspond with the upright retaining tabs118on the lower housing28. A pair of engaging tabs130are formed on the bottom surface of the upper housing30that corresponding to the retaining tabs120on the lower housing28. In operation, the upper housing30is oriented at a slight upward angle so that the retaining surfaces132engage the retaining tabs118. The upper housing is then rotated about the retaining surfaces132so that the engaging tabs130pass over the tabs120. To remove the upper housing30, the sides of the upper housing30are pulled outward while the upper housing30is rotated up and forward about the retaining surfaces132until the upper housing30can be removed. This design facilitates easy removal of the upper housing30for access to the lower housing28without the use of tools for routine maintenance. In an alternate embodiment, the upright retaining tabs118can be replaced with commonly known ¼ turn fasteners that also facilitate removal of the upper housing30without the use of tools.

A belt chamber160is also integrally formed in the lower housing28and provides a space for a brush belt162to mechanically connect the rotating motor shaft24with the brush roll assembly34positioned in the brush chamber32in a conventional manner. A working airflow conduit passage166is integrally formed through the lower housing28to provide a space for the foot conduit40(FIG. 3) to pass therethrough in a conventional manner. In an alternate embodiment, the foot conduit40is integrally formed by the upper and lower housings30,28and no additional parts are needed to create the working air flow path through the base assembly14.

Referring toFIG. 6, the upright assembly12is pivotally supported on the base assembly14via a pair of snap-in bushings151. The bushings151further comprise a bearing surface153, a pair of opposed tongues155, and a resilient snap that includes a lip157. The lower housing28further comprises a bushing support300that includes a pair of opposed grooves302, an arcuate portion304that corresponds with the bearing surface153, and a latch surface306that corresponds with the lip157. To assemble the upright assembly12to the base assembly14, a bushing151is placed over a pivot pin308(FIG. 3) formed on a lower portion of the upright assembly12, on either side of the motor cavity20. Each bushing151can be oriented as the upright assembly12is moved toward the base assembly14so that the tongues155engage the grooves302. The upright assembly12is moved downward until the resilient lip157passes below the latch surface306and snaps in place to capture the bushings151on the base assembly14. As can be appreciated, the snap-in bushings151allow the upper housing30to be removed without separating the upright assembly12from the base assembly14.

Referring toFIGS. 7 and 8, a foot-actuated nozzle height adjustment mechanism comprises a carriage assembly150, an actuator disc210, a cam disc212, and a pivot arm219. The carriage assembly150comprises a pivot pins152that rotate within a pivot socket156integrally molded into the lower housing28and a pair of forward freely rotating wheels154. The actuator disc210further comprises a foot pedal215and a plurality of resilient ramped surfaces214that selectively engage a like number of ramped surfaces216on a mating surface of the cam disc212. Both the actuator disc210and cam disc212are rotatably affixed to the base28via a pin217that further keeps the discs210,212in mating contact. A plurality of cam lobes211of varying dimensions surround a boss220formed on a surface of the cam disc212opposite the ramped surfaces216for receiving the pin217. The pivot arm219is integrally molded with the carriage assembly150and slidingly engages the cam lobes211on the inner surface of the cam disc212.

In operation, the foot pedal215is depressed and since it is offset from the pivot pin boss220, the actuator disc210rotates in a counterclockwise direction (when viewed from the perspective ofFIG. 8) which, in turn, rotates the cam disc212via the mating ramped surfaces214,216. As the cam disc212rotates, the cam lobes211move past the pivot arm219and the pivot arm219comes to rest in the next cam lobe recess formed between two cam lobes211. Since the cam lobes211vary in height, the carriage assembly150rotates about the pivot axis152causing the wheels154move either away from or towards a bottom surface of the lower housing28. When the foot pedal215is released, the pivot arm219holds the cam disc212in place and a torsion spring (not shown) forces the actuator disc210in a clockwise direction whereby the resilient ramped surfaces214slide past the cam ramped surfaces216and come to rest in mating relation with the next ramped surface214.

FIGS. 8A-Bare schematic side views of the operation of the nozzle height adjustment fromFIGS. 4,7, and8. Actuation of the nozzle height adjustment mechanism results in changing the position of the carriage assembly150relative to the lower housing28. Specifically, the pivot pins152act as a fixed fulcrum point about which the carriage assembly150rotates, with the pivot arm219and the wheels154having a fixed angular relationship to each other. The pivot arm219is similar to a lever, in that changing the position of the pivot arm219(which is dependent on which cam lobe recess formed between two adjacent cam lobes211the pivot arm219is in) results in changing the position of the wheels154. Movement of the wheels154away from or towards a bottom surface of the lower housing28raises or lowers the front portion of the lower housing28relative to a floor surface F, which necessarily adjusts the height of the suction nozzle38relative to the floor surface F.FIGS. 8A-8Bshow the movement of the nozzle height adjustment between a first lowered position in which the suction nozzle38is at a height H1from the floor surface F (FIG. 8A) and a second raised position in which the suction nozzle38is at a greater height H2from the floor surface F (FIG. 8B).

Referring toFIGS. 9 and 10, a belt or drive disengaging device159comprises a first plate161that is mounted for rotation about the motor cavity20having motor shaft24extending therethrough. A crescent shaped bearing surface163is attached in an offset fashion to the first plate161. A spring167is connected at one end to the first plate161and at the other end to a location on the base assembly14to bias the belt disengaging device159to an engaged position. A second plate165is mounted for rotation about a pivot pin175attached to the lower housing28and has an engagement pin173extending orthogonally therefrom. The second plate165is biased in a counterclockwise direction as viewed inFIG. 9by a spring strap177that is fixed at one end to the periphery of the second plate165through pin179and at the other end to the periphery of the first plate161through a pin181. The spring strap177is weaved between the two plates161,165so that the two plates161,165move in an interrelated fashion. A foot pedal204for actuating the belt disengaging device159is provided on the exterior of the base assembly14and comprises a shaft206that extends through the upper housing28for engagement with the engagement pin173. With the belt disengaging device159in the position shown inFIG. 9, the crescent surface163is generally positioned between the motor shaft24and the brush roll assembly34so that the belt162rides on the motor shaft24and drives the brush roll assembly34. Referring toFIG. 10, when pressure is applied to the foot pedal204, the shaft206moves linearly in a substantially vertical direction such that the engagement pin173is forced downwardly. The downward force overcomes the spring bias and rotates the second plate165approximately 90 degrees in a counterclockwise direction. The interconnection of the first and second plates161,165provided by the spring strap177causes the first plate161to rotate approximately 90 degrees in a counterclockwise direction. As the first plate161is rotated, the crescent bearing surface163rotates into contact with and slightly stretches the belt162away from the shaft24until the shaft24is between the crescent bearing surface163and the brush roll assembly34, effectively disengaging the brush roll assembly34. A detent device (not shown) maintains the pedal204in the depressed position shown inFIG. 10and thus maintains the belt disengaging device159in the disengaged position. To engage the brush roll assembly34, the foot pedal204is again depressed to release the first plate161back to the original position.

While the base assembly14is illustrated as comprising the nozzle height adjustment mechanism shown inFIGS. 7 and 8, other adjustment mechanisms can be used and a few examples of alternate embodiments of suitable nozzle height adjustment mechanisms are illustrated inFIGS. 11-16. Referring toFIGS. 11 and 12, a first alternate embodiment300comprises a carriage assembly302, an actuator disc304, and a cam disc306. The carriage assembly300is pivotally connected to the lower housing28through a pivot axis308and comprises a pair of wheels310and a pivot arm312. The actuator disc304and cam disc306are received in a bracket314affixed within the base assembly14such that the discs304,306are kept in mating contact. The bracket314comprises two upstanding portions316, between which the actuator disc304and cam disc306are mounted by inserting a pin318or other suitable fastener through a pair of aligned holes320, a pivot arm slot322, and a spring arm slot324. The actuator disc304further comprises a foot pedal326, a spring arm328and a pair of resilient ramped surfaces330that selectively engage a plurality of generally rigid ramped surfaces232on a mating surface of the cam disc306. On the side of the cam disc306opposite the ramped surfaces232, a plurality of cam lobes334of varying dimensions surround a boss336for receiving pin318. The pivot arm312engages the cam lobes334on the cam disc306. The spring arm328is received in the spring arm slot324and biases the actuator disc in a counterclockwise direction with respect to the orientation ofFIG. 11. In operation, the foot pedal326is depressed and the actuator disc304rotates in a clockwise direction with respect to the orientation ofFIG. 11which, in turn, rotates the cam disc306via the mating ramped surfaces330,332. As the cam disc306rotates, the cam lobes334move past the pivot arm312and the pivot arm312comes to rest in the next cam lobe recess formed between two cam lobes334. Since the cam lobes334vary in height, the carriage assembly302rotates about the pivot axis308, causing the wheels310move either away from or towards a bottom surface of the lower housing28. When the foot pedal326is released, the pivot arm312holds the cam disc306in place and the spring arm328forces the actuator disc304in a clockwise direction whereby the resilient ramped surfaces330slide past the rigid ramped surfaces332and come to rest in mating relation with the next ramped surface332.

Referring toFIG. 13, a second alternate embodiment of a nozzle height adjustment mechanism comprises a rotating drum168with a plurality of ratcheted detents170, a foot pedal172, a down actuator rod174, and an up actuator rod176. The drum168and the foot pedal172both rotate about separate bearing surfaces integrally molded in the lower housing28. The foot pedal172is pivotally mounted on a pin178. Both the up and down actuator rods174,176further comprise a pedal engagement surface180on one end and a ratchet engagement surface182on the other. The up actuator rod176further comprises a spring member184that biases the rod176into engagement with the ratchet detents170. The down actuator rod174is rotatably attached to an upper end of the foot pedal172. A plurality of steps186are formed on the surface of the drum168adjacent the ratchet detents170and engage with the carriage assembly150(FIG. 4) as previously described. More specifically, as shown inFIG. 13A-B, the pivot arm219of the carriage assembly150can engage one of the steps186, just as the pivot arm219engaged one of the cam lobes211as shown inFIG. 8A.

In operation, an upper portion of the foot pedal172is pressed, and the foot pedal pivots about the pin178, thereby displacing the down actuator rod174and forcing the ratchet engagement surface182into the ratchet detent170. This causes the drum168to rotate in a counterclockwise direction whereby the ratchet engagement surface182on the up actuator rod176rides over the ratchet detent170until the up actuator rod176clears the ratchet detent170and the spring member184forces the ratchet engagement surface182on the up actuator rod176into the next ratchet detent170. This action rotates the drum168the distance of one ratchet detent170, which displaces the step186and moves the carriage assembly150closer to the bottom surface of the lower housing28to reduce the nozzle height above the surface to be cleaned. Conversely, when the lower surface of the foot pedal172is depressed, the foot pedal172pushes the up actuator rod176to release engagement surface182and pulls the down actuator rod174away from the ratchet detents170so that the drum168rotates in an opposite direction. The steps186then push the carriage assembly150away from the bottom surface of the lower housing28to increase the nozzle height above the surface to be cleaned. In this way, nozzle height can be adjusted incrementally in either direction as desired.

FIGS. 13A-Bare schematic side views of the operation of the second alternate nozzle height adjustment mechanism fromFIG. 13. Actuation of the nozzle height adjustment mechanism results in changing the position of the carriage assembly150relative to the lower housing28. Specifically, the pivot pins152act as a fixed fulcrum point about which the carriage assembly150rotates, with the pivot arm219and the wheels154having a fixed angular relationship to each other. The pivot arm219is similar to a lever, in that changing the position of the pivot arm219(which is dependent on which step186the pivot arm219is in) results in changing the position of the wheels154. Movement of the wheels154away from or towards a bottom surface of the lower housing28raises or lowers the front portion of the lower housing28relative to a floor surface F, which necessarily adjusts the height of the suction nozzle38relative to the floor surface F.FIGS. 13A-Bshows the movement of the nozzle height adjustment between a first lowered position (FIG. 13A) in which the suction nozzle38is at a height H1from the floor surface F and a second raised position (FIG. 13B) in which the suction nozzle38is at a greater height H2from the floor surface F. In the first lowered position ofFIG. 13A, the pivot arm219engages a first step186on the drum168. To move to the second raised position ofFIG. 13B, the foot pedal172is pressed as described above with respect toFIG. 13, which causes the drum168to rotate in a counterclockwise direction and move the pivot arm219from one step186to the next adjacent step186. The steps186can have different dimensions, such that movement between steps changes the angular position of the pivot arm219, thereby raising or lowering the wheel154relative to the lower housing28.

Referring toFIG. 14, a third alternate embodiment of a nozzle height adjustment mechanism is illustrated, and comprises a ratcheting nozzle height adjustment mechanism340. The height adjustment mechanism340comprises a linear track342with a plurality of ratchet detents344formed within a trapezoidal housing346. A pair of grooves348run along either side of the linear track342. Both the linear track342and the grooves348are aligned parallel to an upper surface of the trapezoidal housing346, leaving a ramped engagement surface350at a lower surface. A plurality of detents352are equally spaced along the upper surface of the trapezoidal housing346and slideably engage a resilient tab (not shown) on the lower housing28. The trapezoidal housing346is slideably affixed to the lower housing28in a horizontal orientation via the grooves348so that the upper surface travels in a generally horizontal plane relative to the surface to be cleaned. A two position foot pedal354is pivotally affixed to the lower housing28by a pin360and acts on an actuation rod356with a corresponding ratchet engagement surface358.

The operation is similar to the second alternate embodiment shown inFIG. 13, wherein when either the upper portion or the lower portion of the foot pedal354is pressed, the ratchet engagement surface358respectively engages either the upper or lower set of ratchet detents344formed on the linear track342and pushes the trapezoidal housing346relative to the lower housing28along the grooves348until one of the detents352is captured by the resilient tab on the lower housing28, which forces the ratchet engagement surface358into the next ratchet detent344. Since the movable ramped engagement surface350directly engages the pivoting height adjustment carriage assembly150shown inFIG. 4, as the trapezoidal housing346moves horizontally, the carriage assembly150is forced away from or up towards the bottom surface of the lower housing28to effectively raise and lower the nozzle height above the surface to be cleaned.

FIGS. 14A-Bare schematic side views of the operation of the third alternate nozzle height adjustment mechanism350fromFIG. 14. Actuation of the nozzle height adjustment mechanism350results in changing the position of the carriage assembly150relative to the lower housing28. Specifically, the pivot pins152act as a fixed fulcrum point about which the carriage assembly150rotates, with the pivot arm219and the wheels154having a fixed angular relationship to each other. The pivot arm219is similar to a lever, in that changing the position of the pivot arm219(which is dependent on which portion of the ramped engagement surface350the pivot arm219is engaging) results in changing the position of the wheels154. Movement of the wheels154away from or towards a bottom surface of the lower housing28raises or lowers the front portion of the lower housing28relative to a floor surface F, which necessarily adjusts the height of the suction nozzle38relative to the floor surface F.FIGS. 14A-Bshows the movement of the nozzle height adjustment between a first lowered position (FIG. 14A) in which the suction nozzle38is at a height H1from the floor surface F and a second raised position (FIG. 14B) in which the suction nozzle38is at a greater height H2from the floor surface F. In the first lowered position ofFIG. 14A, the pivot arm219engages the lower end of the ramped engagement surface350. To move to the second raised position ofFIG. 14B, the foot pedal354is pressed as described above with respect toFIG. 14, which causes the trapezoidal housing346to be pushed along the grooves348relative to the lower housing28. Movement of the trapezoidal housing346changes what portion of the engagement surface350that the pivot arm219engages, such that rearward movement of the trapezoidal housing346as shown inFIG. 14Blowers the wheel154relative to the lower housing28and increases the height of the suction nozzle38.

Referring toFIGS. 15 and 16, a fourth alternate embodiment of a nozzle height adjustment mechanism is illustrated. A nozzle height adjustment aperture136is integrally formed through the upper housing30and is aligned with a carriage assembly138pivotally mounted to the lower housing28. A height adjustment actuator140comprises an actuator knob142on one end and an engaging surface144on the other. The engaging surface144is comprised of a series of cam lobes146that vary in height relative to the actuator knob142. The engaging surface144abuts a corresponding engaging surface148on a height adjustment carriage assembly138. A plurality of rectangular engagement keys141protrude from the engaging surface144. The engagement keys141correspond with a like number of engagement slots143formed in the height adjustment aperture136. The keys141and slots143are oriented so that the height adjustment actuator140can be inserted in one orientation only. To assemble the height adjustment assembly, the height adjustment actuator140is positioned over the aperture136so that the keys141align with the slots143. The actuator140is pushed down until a lower surface145of the knob142abuts an upper surface147of the aperture136. The actuator140is then rotated approximately 90 degrees, whereby the keys141no longer align with the slots143and effectively locking the actuator140to the upper housing30. This locking design and mating of the lower surface145to the upper surface147serves to effectively seal the generally cylindrical portion of the actuator140from dirt and debris that could otherwise enter the assembly and cause binding. Additionally, a plurality of grooves366are provided on the upper surface147of the aperture136and allow any dirt or debris that accumulates around the nozzle height adjustment mechanism to fall between the actuator140and the aperture136via the grooves.

The carriage assembly138further comprises a pivot pins362that rotate within the pivot socket156integrally molded into the lower housing28and a pair of forward freely rotating wheels364. As the knob142is rotated within the aperture136, the cam lobes146interface with the upper surface147of the aperture136, thus raising or lowering the engaging surface144relative to the lower housing28. As the engaging surface144is moved down, the carriage assembly138rotates downwardly about the pivot points362, pushing the carriage138down toward the surface and effectively raising the suction nozzle38away from the surface to be cleaned. Conversely, as the engaging surface is raised, the carriage138rotates upwardly toward the lower housing28thus minimizing the distance between the suction nozzle38and the surface to be cleaned.

While the base assembly14is illustrated as comprising the belt disengaging mechanism shown inFIGS. 9 and 10, other belt drive disengaging mechanisms can be used and a few examples of alternate embodiments of suitable belt or drive disengaging mechanisms are illustrated inFIGS. 17-20. Referring toFIG. 17-19A, a first alternate embodiment370generally comprises a bracket372, a pair of belt disengaging pins374,376for disengaging the belt162from the motor shaft24, an actuator378for actuating the belt disengager370, and a linkage380between the belt disengaging pins374,376and the actuator378. The bracket372comprises a linear guide track382, an upper curved guide track384, a lower curved guide track386and a plurality of flanges388that facilitate mounting the bracket372within the base assembly14. The actuator378comprises a foot pedal390provided on the exterior of the base assembly14and that is rotatably coupled to the bracket372by a foot pedal shaft392. A retainer spring393mounts the foot pedal shaft392to the bracket372. The foot pedal shaft392has a rear orthogonal extension394pivotally coupled to the linkage380by a first pivot pin396. The linkage380comprises a pair of spaced toggle links398,400and a pair of curved arms402,404. The toggle links398,400are attached at one end to the rear extension394by the first pivot pin396and at the other end to one end of the curved arms402,404by a second pivot pin406, such that the rear extension394and the curved arms402,404are both positioned between the toggle links398,400. The other end of the curved arms402,404each comprise one of the belt disengaging pins374,376, respectively. The second pivot pin406is slidingly received in the linear guide track382, the belt disengaging pin374on the upper curved arm402is slidingly received in the upper curved guide track384, and the belt disengaging pin376on the lower curved arm404is slidingly received in the lower curved guide track386. A belt guide408is provided between the belt162and the bracket372, and prevents the belt162from rubbing against the bracket372and creating unwanted friction. A spring410on the foot pedal shaft392having an arm portion412wrapped around the rear extension394biases the foot pedal390, and thus the entire belt disengager370, to the position shown inFIGS. 18 and 18A, wherein the belt162is engaged with the motor shaft24and drives the brush roll assembly34. When pressure is applied to the foot pedal390, the foot pedal shaft392rotates clockwise and the rear extension394pivots upwardly with respect to the orientation ofFIG. 18A. The pivoting motion of the rear extension394causes the toggle links398,400pivot clockwise about the first pivot pin396and the second pivot pin406to slide within the linear guide track382, which in turn causes the curved arms402,404to slide within their respective curved guide tracks384,386from the position shown inFIG. 18Ato the position shown inFIG. 19A. As the curved arms402,404move, the belt disengaging pins374,376engage the belt162and lift it from engagement with the motor shaft24, as can be seen inFIG. 19A, thereby disengaging the belt drive mechanism. The foot pedal390or another portion of the actuator378can have a detent device (not shown) to maintain the foot pedal390in the depressed position shown inFIGS. 19 and 19Aand thus maintain the belt in the disengaged position.

Referring toFIG. 20, in a second alternate embodiment of a drive disengaging mechanism, the motor/fan assembly22is fixedly mounted vertically in the base assembly14. A generally circular flywheel250is fixedly attached to and rotates with the motor shaft24about a rotational axis264. The flywheel includes a face266in a plane perpendicular to the rotational axis264. A drive engaging arm252is pivotally attached to the lower housing28and comprises foot pedal254on one end and a pivot point256on the other end. A belt drive hub258is mounted to the drive engaging arm252, orthogonally to the flywheel250, for selective engagement therewith. The belt162is in mechanical communication with a drive hub shaft260extending from the drive hub258and the brush roll assembly34. The drive engaging arm252is biased by a drive engaging spring262to place the belt drive hub258in selective contact with the fly wheel250. In operation, the motor shaft24rotates when power is applied to the motor/fan assembly22, causing the flywheel250to rotate. The drive engaging spring262forces the drive engaging arm252to pivot about the pivot point256causing the belt drive hub258to engage the face266of the flywheel250. As illustrated, a circumferential edge268of the belt drive hub258may couple with the face266for rolling contact therewith. The belt drive hub258rotates, which in turn causes the drive hub shaft260to rotate, rotating the belt162and ultimately the brush roll assembly34. A commonly known latch (not shown) can be incorporated to secure the drive engaging arm252away from the flywheel250when the user steps on the foot pedal254, effectively disengaging the brush drive mechanism when the user desires to use the vacuum cleaner10without the aid of a rotating brush roll assembly34.

As can be appreciated, the drive engaging arm252can also pivot laterally so that the belt drive hub258can change contact positions on the flywheel250. For example, when the belt drive hub258is positioned near the center of the flywheel250, the belt drive hub258will rotate slowly. As the belt drive hub258is moved toward the outer perimeter of the flywheel250the speed of the belt drive hub258, and correspondingly the speed of the brush roll assembly34, increases thus providing a variable speed brush control.

While the base assembly14is illustrated as comprising the suction nozzle38shown inFIG. 4, other suction nozzles can be used, and a few examples of alternate suction nozzles are illustrated inFIGS. 21 and 22. Referring toFIG. 21, a first alternate embodiment comprises a suction nozzle extension128extends in a rearward direction at either side of the lower housing28, forming a generally U-shaped suction nozzle58. In this way, the suction nozzle58surrounds the forward portion of the lower housing28for cleaning additional surface area as well as improved edge cleaning In addition, an optional pet hair removal device129is included near the suction nozzle58and is formed of a rubber or plastic material create a static charge when exposed to frictional forces are mounted around the suction nozzle58to further enhance cleaning Alternatively, the pet hair removal devices129can be made of a conventional lint brush material. A more complete description of suitable pet hair removal devices can be found in U.S. Provisional Patent Application 60/594,773 which is incorporated herein by reference in its entirety.

Referring toFIG. 22, a second alternate embodiment of a suction nozzle60for the base assembly14is illustrated, wherein the suction nozzle60comprises a plurality of partitions62sectioning the suction nozzle60into a plurality of individual suction chambers64across the width of the suction nozzle60. Each suction chamber64has an outlet port66in communication with a common manifold conduit68in fluid communication with the motor fan assembly22via the foot conduit40or other suitable means.

Referring toFIGS. 23-26, various embodiments of the brush roll assembly34are illustrated. It is within the scope of this invention to incorporate any of the following brush roll assemblies on the base assemblies14previously described. Referring toFIG. 23, a first embodiment of the brush roll assembly34comprises a generally cylindrical brush dowel222with a bearing surface224on both ends and a belt engagement surface226around the circumference near one end that communicates with the belt162. A plurality of flexible bristles228are inserted into the outer circumference of the brush dowel222forming individual tufts230. Typically the bristles228are finished by trimming the bristles228after they are inserted into the brush dowel222resulting in a squared off end of the bristle228. A plurality of tufts230are arranged in a generally helix fashion in rows232along the outer circumference of the brush dowel as is typical in the vacuum art. In addition, the brush roll assembly can be biased so that a constant down force is provided to ensure even and consistent contact with the surface to be cleaned as is disclosed in U.S. Pat. No. 6,934,993, issued Aug. 30, 2005, which is incorporated herein by reference in its entirety. As can be appreciated, the number of bristles228used to form each tuft230, the number of tufts230used to form each row232, and the number of rows232used on the brush dowel222can all be varied to create an optimum agitation device. Furthermore, the helix angle of the rows232can be increased to give a high helix angle pattern resulting in a greater bristle228surface area. In an alternate embodiment, the bristle end that engages the surface to be cleaned is rounded and the tufts230are created by inserting the bristle228into the brush dowel222so that a finished diameter is created upon insertion with no need for finish trimming. Alternatively, the bristle228ends can be rounded after trimming similar to the configuration of the bristles of a toothbrush. The rounded bristle228end creates a smoother bristle surface area that is preferred on the more delicate surface finishes such as wood and carpet.

Referring toFIG. 24, in a second embodiment, where like elements are indicated by the same reference numeral bearing a prime symbol (′), the tufts230′ are attached to a flexible support234forming a bristle strip236that is removably inserted into a channel238formed in the dowel222′. A number of different bristle strips236that vary the material, length, or stiffness of the bristles228′ can be used to give the user options based upon their particular cleaning needs. For example, softer bristles228′ are preferred on more delicate floors such as wood or delicate carpets to prevent damage while stiffer bristles228′ are desired on hard tiled surfaces to more aggressively remove debris that is stuck to the surface to be cleaned. In addition, the use of bristle strips236provides for easy maintenance of the brush because the bristles can be replace without removing the brush roll assembly34′ from the base assembly14.

Referring toFIG. 25, in a third embodiment wherein like elements are identified by the same reference numerals bearing a double prime symbol (″), each tuft230″ is cut on an angle so that the angled surface is in contact with the surface to be cleaned. This allows for more of the bristle228″ends to remain in contact with the surface to be cleaned resulting in improved cleaning performance. Alternatively, the tuft230″ can be trimmed at an angle on both sides so that a more flexible tuft230″ is created. In yet another embodiment, a stiffener240is embedded in the dowel222″ behind the tuft230″ relative to the direction of rotation that effectively creates a stiffer tuft230″ while improving dynamic flexing characteristics. Alternatively, the stiffener240can be integrally formed in the brush dowel222″ or can be mechanically fastened to the brush dowel222″ after the tufts230″ have been inserted via commonly known methods such as rivets, screws, or adhesives. Furthermore, the stiffeners240can be formed as a continuous strip that extends between the tufts230″ or can be individually placed behind each tuft230″. Additionally, the tufts230″ can be stiffened by counter boring each tuft to provide the wall required to stiffen the bristle228″.

Referring toFIG. 26, in a fourth embodiment wherein like elements are identified by the same reference numerals bearing a triple prime symbol (′″) a plurality of static strips242are formed of a suitable rubber or plastic material that creates a static charge when exposed to frictional forces. The static strips242are inserted into the channels in the dowel222′″ as previously described. Different materials create different static charges that are suitable for attracting specific debris types such as dust, pollens, pet hair, and dirt. One or more static strip242of the same or different material types can be used in the dowel222′″ depending upon the user's preference.