MULTI-ROLLER SURFACE CLEANER SYSTEMS, METHODS, AND DEVICES WITH LINEARLY ADJUSTABLE FLOATING ROLLERS

INTRODUCTION

[0001]The present disclosure relates generally to surface cleaning systems that generate suction to remove debris from surfaces. In particular, aspects of this disclosure relate to manually operated vacuum cleaners with multi-roller cleaning heads.

[0002]A traditional vacuum cleaner is an electropneumatic device that generates a gaseous-pressure differential for cleaning hard surfaces, such as tile and wood flooring, and soft surfaces, such as carpet and upholstery. While conventionally built as a “dry” type cleaning apparatus limited to removing dirt, dust, and solid debris, some surface-cleaning vacuums are adapted as “wet” type fluid recovery systems that also extract stains and other liquids from a target surface to be cleaned. Vacuum cleaners typically include a suction nozzle that is moved across the target surface for ingesting debris, a recovery container for stowing the removed debris, and a fluid conduit that fluidly connects the suction nozzle to the recovery container. Debris-laden air is thus drawn from the target surface, through the suction nozzle and connecting fluid conduit, and into the recovery container for storage and subsequent disposal. Many vacuum cleaners employ an agitator to loosen debris on the target surface so that the debris is more easily ingested into the suction nozzle. In most cases, the agitator is a single, motor-driven brushroll that rotates within a base assembly (or “cleaning head”) adjacent the nozzle. Vacuum cleaners may also include auxiliary agitators for providing additional agitation to the target surface. One type of auxiliary agitator is a secondary “leading” brushroll that is positioned forward of a primary “trailing” brushroll and acts to sweep dirt and debris into the suction path of the suction nozzle.

SUMMARY

[0003]Presented herein are multi-roller surface cleaning heads with linearly adjustable floating rollers, methods for making and methods for using such surface cleaning heads, and vacuum-based surface cleaning systems with such cleaning heads. In a non-limiting example, a multi-roller surface cleaning head contains both a motor-driven primary brushroll with a primary roller diameter, and floating secondary roller located forward of the primary brushroll and having a secondary roller diameter that is smaller than the primary roller diameter. To facilitate removal of large debris, the floating secondary roller has a dynamically adjustable roller height and, thus, automatically lifts when traversing large debris and subsequently drops under the force of gravity to maintain suction pressure when traversing small debris. The floating roller may be a soft-padded roller, i.e., sans brushes, bristles, nubs, etc., to optimize cleaning head suction pressure. For friction-driven configurations, frictional forces generated by the target surface drive rotation of the floating secondary roller. In this instance, plain bearings may be incorporated into opposing ends of the floating secondary roller to facilitate smooth rotation of the secondary roller. Each of these bearings may be slidably mounted in a respective linear slot that is recessed into or extends through a mounting bracket or plate of the cleaning head's main housing.

[0004]For motor-driven configurations, driving torque from a roller motor is transferred from a primary roller to a secondary roller via a belt-drive powertrain system. In this instance, the belt-drive system may include a central axle bearing both a first gear/sheave drivingly connected via a first belt to a primary gear/sheave of the primary roller, and a second gear/sheave drivingly connected via a second belt to a secondary gear/sheave of the secondary roller. For an optimized mechanical advantage, the first gear/sheave may have a first diameter that is larger than a second diameter of the second gear/sheave. In addition, a third diameter of the primary gear/sheave may be less than the first diameter of the first gear/sheave, and a fourth diameter of the secondary gear/sheave may be greater than the second diameter of the second gear/sheave and less than the first diameter of the first gear/sheave. To facilitate floating of the secondary (“lead” or “leading”) roller, a leading axle shaft of the leading roller may be slidably mounted into a first set of linear slots in a pair of mounting plates or brackets of the cleaning head. Likewise, the central axle may be slidably mounted into a second set of linear slots in the mounting plates/brackets of the cleaning head. The second set of linear slots may be tilted at an oblique angle with respect to the first set of linear slots.

[0005]Aspects of this disclosure are directed to multi-roller cleaning heads with linearly adjustable floating rollers for vacuum-based surface cleaning systems. As used herein, the terms “surface cleaning system” and “surface cleaner” and “extraction cleaner”—including variations and permutations thereof—may be used interchangeably and synonymously to include any relevant vacuum-based cleaner system, including upright, canister, stick, handheld, and pod-type form factors of the wet or dry extraction type in both corded and cordless configurations, as some non-limiting examples. In an example, there is presented a surface cleaning head for a surface cleaning system, which includes a recovery container, a suction device fluidly connected to the recovery container via a fluid conduit, and other original or aftermarket equipment.

[0006]Continuing with the foregoing example, the surface cleaning head includes a main (base) housing with a pair of linear pin slots, a nozzle inlet through which debris is ingested from a target surface, and a connector port that is fluidly connected to the nozzle inlet and operatively couples with the cleaning system's fluid conduit to thereby fluidly connect the cleaning head to the suction device. A first (main) roller is rotatably attached to the main housing, interposed between the nozzle inlet and connector port. Also attached to the main housing is a roller motor (e.g., 2-stage, direct-current (DC) electric motor) that is drivingly connected to and operable to selectively rotate the first roller. A second (auxiliary) roller is also rotatably attached to the main housing, oriented substantially parallel to the first roller. The second roller includes an elongated roller shaft with a pair of mounting pins projecting from opposing ends of the roller shaft. Each mounting pin is slidably mounted in a respective one of the housing's linear pin slots such that the second roller freely floats, e.g., in a reciprocating linear motion, within the main housing.

[0007]Additional aspects of this disclosure are directed to extraction cleaner systems equipped with multi-roller surface cleaning heads having linearly adjustable floating rollers. In an example, there is presented a surface cleaning system for removing dirt and debris from a target surface. The surface cleaning system includes a recovery container that is removably attached to a main cleaner body and stows therein debris extracted from the target surface. Also attached to the cleaner body is a suction device that is fluidly coupled to the recovery container and operable to generate a suction force sufficient to draw dirt and debris into the recovery container. A hose is attached to the cleaner body and fluidly connected to both the recovery container and the suction device.

[0008]The aforementioned surface cleaning system also includes a surface cleaning head that is movably mounted on, integrally formed with, or otherwise attached to the cleaner body. The surface cleaning head includes a main housing with a pair of linear pin slots, a nozzle inlet that ingests debris from the target surface, and a connector port that is fluidly connected to the nozzle inlet and coupled to the hose to thereby fluidly connect the surface cleaning head to the recovery container and suction device. A main (trailing) roller is rotatably attached to the main housing, interposed between the nozzle inlet and the connector port. Also attached to the main housing is a roller motor that is drivingly connected to and operable to selectively rotate the main roller. An auxiliary (leading) roller is rotatably attached to the main housing, oriented substantially parallel to and forward of the main roller. This auxiliary roller includes a roller shaft with a pair of mounting pins projecting from opposing longitudinal ends of the roller shaft. Each mounting pin is slidably mounted in a respective one of the main housing's linear pin slots such that the auxiliary roller floats within the main housing. With this arrangement, the auxiliary roller slides unobstructed along a rectilinear path between a lowered position and a raised position such that the auxiliary roller is biased by gravity from the raised position to the lowered position, i.e., without the use of a return spring or other biasing mechanism.

[0009]Aspects of this disclosure are also directed to methods for manufacturing and methods for operating any of the herein disclosed surface cleaning systems, cleaner heads, roller drivetrains, etc. In an example, a method is presented for assembling a surface cleaning head for a surface cleaning system. This representative method includes, in any order and in any combination with any of the above and below disclosed options and features: receiving a main housing of the surface cleaning head, the main housing having first and second linear pin slots, a nozzle inlet configured to ingest debris from a target surface, and a connector port fluidly connected to the nozzle inlet; coupling the connector port with a fluid conduit of the surface cleaning system to thereby fluidly connect the surface cleaning head to the suction device; rotatably attaching a first roller to the main housing such that the first roller is interposed between the nozzle inlet and the connector port; attaching a roller motor to the main housing; drivingly connecting the roller motor to the first roller, the roller motor being operable to selectively rotate the first roller; and rotatably attaching a second roller to the main housing substantially parallel to the first roller, the second roller including a roller shaft with first and second mounting pins projecting from opposing first and second ends, respectively, of the roller shaft and slidably mounted in the first and second linear pin slots, respectively, such that the second roller floats in the main housing.

[0010]For any of the disclosed systems, methods, and devices, the second roller may slide unobstructed within the main housing's linear pin slots from a first (lowered) position to a second (raised) position and back down to the lowered position. In this instance, the second roller may be biased by gravity from the raised position to the lowered position sans a spring force of a spring (e.g., helical spring, leaf spring, air spring, etc.). As another option, the cleaning head's main housing may include a nozzle housing shell, which at least partially defines the nozzle inlet, and a connector housing shell, which is mounted to the nozzle housing shell and at least partially defines the connector port. In this instance, the first and second rollers are both rotatably mounted inside the nozzle housing shell. The nozzle housing shell may be a single-piece structure that includes an integral roller housing with a main roller compartment, which mounts therein the first roller, and a leading roller compartment, which mounts therein the second roller. The cleaning head's main housing may also include a single-piece base plate that rigidly attaches to both the connector housing shell and the nozzle housing shell. Once attached, the base plate and roller housing may cooperatively define the nozzle inlet, whereas the nozzle housing shell and the connector housing shell may cooperatively define the connector port.

[0011]For any of the disclosed systems, methods, and devices, the first roller may have a first roller diameter and the second roller may have a second roller diameter that is smaller than the first roller's diameter. As another option, the first roller may be a brushroll that includes multiple brush-bristle tufts, and the second roller may be a padded roller that lacks brush bristles, e.g., to maintain suction pressure at the nozzle inlet. It may be desirable that the second roller lacks a driving engagement with a motor and, thus, is friction-driven by frictional forces generated by the target surface when moving the cleaning head across the target surface. In this instance, the second roller may include a pair of friction wheels, each of which is rigidly secured to a respective end of the roller shaft. Each of the mounting pins of the second roller may be integrally formed with and projects axially outward from a respective one of the friction wheels.

[0012]For any of the disclosed systems, methods, and devices, the surface cleaning head may also include a belt-drive system with a central axle that is attached to the main housing such that the central axle is parallel to and interposed between the first and second rollers. The central axle bears a pair of torque-transmitting “wheels” (e.g., gears, sheaves, sprockets, etc.), including a first (axle) wheel that is drivingly connected via a first belt to a first (roller) wheel of the first roller, and a second (axle) wheel that is drivingly connected via a second belt to a second (roller) wheel of the second roller. The first and second axle wheels may rotate in unison with each other and with the central axle. In the same vein, the first roller wheel may rotate in unison with the first roller, and the second roller wheel may rotate in unison with the second roller. In this instance, the first axle wheel may have a first axle diameter, the second axle wheel may have a second axle diameter that is smaller than the first axle's diameter, the first roller wheel may have a first roller diameter that is smaller than the first axle's diameter, and the second roller wheel may have a second roller diameter that is smaller than the second axle's diameter.

[0013]For any of the disclosed systems, methods, and devices, the main housing may also include a pair of linear axle slots within which is slidably mounted the central axle to translate along a first rectilinear path. In this instance, the second roller may translate along a second rectilinear path that is oblique to the first rectilinear path (e.g., offset angle of about 20° to) 30°. As another option, the first roller may be pivotably attached to the central axle via a first pair of control arms, and the second roller may be pivotably attached to the central axle via a second pair of control arms. In this instance, the first and second rollers may share a substantially identical diameter, whereas the first roller may be bristled and the second roller may be covered in a compressible “fluffy” material. It may be desirable that the first and second axle wheels and the first and second roller wheels be sprockets or gears, and the interconnecting first and second belts be toothed belts.

[0014]The above Summary does not represent every embodiment or every aspect of the present disclosure. Rather, the Summary merely provides an exemplification of some of the novel concepts and features set forth herein. The above features and advantages, and other features and attendant advantages of this disclosure, will be apparent from the following Detailed Description of illustrated examples and representative modes for carrying out the present disclosure when taken in connection with the accompanying drawings and appended claims. Moreover, this disclosure expressly includes any and all combinations and subcombinations of elements and features presented above and below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic diagram of a representative vacuum-based surface cleaning system with which novel features of this disclosure may be practiced in accord with aspects of this disclosure.

[0016]FIG. 2 is an enlarged, perspective-view illustration of a representative surface cleaning system with a representative multi-roller cleaning head with a linearly adjustable floating lead roller in accord with aspects of this disclosure.

[0017]FIG. 3 is a perspective-view illustration of the representative multi-roller cleaning head of FIG. 2 cutaway along line 3-3 to show the floating lead roller in a first (lowered) position.

[0018]FIG. 4 is a perspective-view illustration of the representative multi-roller cleaning head of FIG. 2 cutaway to show the floating lead roller elevated to a second (raised) position.

[0019]FIG. 5 is a perspective-view illustration of the representative multi-roller cleaning head of FIG. 2 cutaway along line 5-5 to show the floating lead roller slidably mounted in linear pin slots inside a main housing of the cleaning head.

[0020]FIG. 6 is a perspective-view illustration of a representative torque-transmitting roller drivetrain system for a multi-roller cleaning head of a vacuum-based surface cleaning system in accord with aspects of this disclosure.

[0021]FIG. 7 is a perspective-view illustration of the representative roller drivetrain system of FIG. 6 shown with a central axle and a leading axle slidably mounted inside respective sets of slots of a mounting plate in accord with aspects of this disclosure.

[0022]The present disclosure is amenable to various modifications and alternative forms, and some representative configurations are shown by way of example in the drawings and will be described in detail below. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the above-enumerated Figures. Rather, this disclosure covers all modifications, equivalents, combinations, permutations, and alternatives falling within the scope of this disclosure as encompassed, for example, by the appended claims.

DETAILED DESCRIPTION

[0023]This disclosure is susceptible of embodiment in many different forms. Representative embodiments of the disclosure are shown in the drawings and will herein be described in detail with the understanding that these embodiments are provided as an exemplification of the disclosed principles, not limitations of the broad aspects of the disclosure. To that extent, elements and limitations that are described, for example, in the Abstract, Introduction, Summary, Description of the Drawings, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise. Moreover, recitation of “first”, “second”, “third”, etc., in the specification or claims is not per se used to establish a serial or numerical limitation; unless specifically stated otherwise, these designations may be used for ease of reference to similar features in the specification and drawings and to demarcate between similar elements in the claims.

[0024]Additionally, unless specifically disclaimed: the singular includes the plural and vice versa; the words “and” and “or” shall be both conjunctive and disjunctive; the words “any” and “all” shall both mean “any and all”; and the words “including,” “containing,” “comprising,” “having,” along with permutations thereof and similar terms, shall each mean “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “generally,” “approximately,” and the like, may each be used herein in the sense of “at, near, or nearly at,” or “within 0-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example. Lastly, directional adjectives and adverbs, such as front, back, left, right, fore, aft, vertical, horizontal, forward, backward, upward, downward, etc., may be with respect to a surface cleaning device that is operatively oriented for cleaning on a horizontal target surface.

[0025]Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views, there is shown in FIG. 1 a schematic diagram of a representative surface cleaning system, which is designated generally at 10 and portrayed herein for purposes of discussion as a manually operated, upright-type vacuum cleaner. The illustrated surface cleaning system 10—also referred to herein as “surface cleaner” or “extraction cleaner”—is merely an exemplary application with which aspects of this disclosure may be practiced. In the same vein, utilization of the present concepts for a lead roller in a two-roller cleaning head should also be appreciated as an exemplary application of the novel concepts disclosed herein. As such, it will be understood that aspects and features of the disclosure may be used for other cleaning head configurations and employed for any logically relevant type of surface cleaning system. Moreover, only select components of the surface cleaning systems and multi-roller cleaning heads are shown and described in additional detail below. Nevertheless, the surface cleaning systems and heads discussed herein may include numerous additional and alternative features for carrying out the various methods and functions of this disclosure.

[0026]FIG. 1 illustrates various functional subsystems of a vacuum-based extraction cleaner tool in the form of a surface cleaning system 10. These functional subsystems may be arranged into any desired configuration, including upright-type extraction devices, canister-type extraction devices, pod-type extraction devices, handheld extraction devices, autonomous and robotic cleaning devices, and commercial cleaners. For instance, any of the herein-described multi-roller surface cleaning heads, such as those presented in FIGS. 2-7, may be incorporated into or adapted to include any of the related features of the surface cleaning system 10 illustrated in FIG. 1, and vice versa. By way of example, a multi-roller surface cleaning head with a linearly adjustable floating lead roller may be adapted to detachably couple to, permanently affix to, or integrally form with a flexible vacuum cleaner hose or main vacuum body, which can form a portion of a suction nozzle and a suction source in a wheeled or carried base of an upright, cannister, handheld, or pod-type extraction device.

[0027]The extraction cleaner 10 of FIG. 1 may be a bipartite architecture with a fluid delivery system 12, which stores and selectively dispenses a cleaning fluid to a surface being cleaned, and a fluid recovery system 14, which removes spent cleaning fluid and debris from the surface being cleaned and stores the recovered cleaning fluid and debris. In this instance, the illustrated fluid recovery system 14 may be composed of an upstream-end suction nozzle 16, a downstream-end vacuum-generating suction source 18, and an optional waste-storing recovery container 20. The suction source 18, which may be in the nature of a motor-fan, positive-displacement, or centrifugal-rotodynamic assembly, is fluidly connected to the suction nozzle 16 and, when desired, generates a working air stream for drawing liquid and debris into the recovery system 14. The recovery container 20, which may be interposed between the suction nozzle 16 and suction source 18, separates and collects liquid and debris from the working airstream for later disposal. A separator 21 can be packaged inside a portion of the recovery container 20 for separating liquid and entrained debris from the working airstream. It should be appreciated that the fluid delivery system 12 may be altogether omitted from the surface cleaning system 10 of FIG. 1, e.g., for dry-type cleaning applications.

[0028]Continuing with the discussion of the representative extraction cleaner 10 system of FIG. 1, the suction source 18 may be any suitable vacuum-generating, electro-mechanical device that is electrically coupled or couplable to a power source 22, such as a rechargeable battery or an electrical outlet. A power switch 24, which may be located between the suction source 18 and the power source 22, is selectively actuable by a user to activate the suction source 18. The suction nozzle 16—through which is drawn dirt, debris, spent cleaning solution, etc.—may be integrated into a base, a tool, or a cleaning head and may be adapted to move over a target surface being cleaned. An optional agitator 26 may be located adjacent to the suction nozzle 16 to disturb the surface being cleaned so that debris is broken up and more easily ingested into the suction nozzle 16. Some non-limiting examples of agitators include a horizontally oriented rotating brushroll, a vertically oriented rotating brushroll, a stationary brush, an array of flexible protuberances, etc.

[0029]Extraction cleaner 10 may operatively interface with any of an assortment of interchangeable attachments and tools to facilitate different cleaning tasks. In FIG. 1, for example, an accessory hose 28 may selectively fluidly couple the suction source 18 to an accessory tool or cleaning attachment 30, such as an extension wand, an upholstery tool, a dusting brush, etc., with a separate suction inlet. In some embodiments, a diverter valve assembly 32 or other diverting mechanism can be provided to selectively redirect fluid communication from the suction source 18 to either the suction nozzle 16 or the accessory hose 28. The accessory hose 28 may also employ a fluid distributor (not shown in FIG. 1) that fluidly connects the fluid delivery system 12 with the tool/attachment 30 to selectively discharge therefrom the cleaning fluid.

[0030]The extraction cleaner's fluid delivery system 12 may be composed of a refillable or interchangeable (first) fluid container 34 at an upstream-end of the system 12, a liquid-dispensing fluid distributor 38 at a downstream-end of the system 12, and a liquid flow-regulating flow control system 36 interposed between the container 34 and distributor 38. The fluid container 34 stores and selectively dispenses therefrom a supply of cleaning fluid. The cleaning fluid may include one or more of any suitable cleaning liquids, such as water, chemical compositions, concentrated detergents, diluted detergents, etc., and mixtures thereof. The flow control system 36 governs the transfer of cleaning fluid from the container 34 to the distributor 38. In the illustrated configuration, the flow control system 36 employs a unidirectional liquid pump 40 to pressurize the fluid delivery system 12, and a flow control valve or valves 42 to control the delivery of cleaning fluid to the distributor 38.

[0031]An actuator 44, which may be in the nature of a manually operated trigger or lever, can be provided to activate the flow control system 36 and dispense fluid to and through the distributor 38. For a normally closed valve assembly, the actuator 44 may be operatively coupled to the valve 42 such that pressing the actuator 44 will open the valve 42. The valve 42 may be an electrically actuated valve device such that an electrical switch 46 located between the valve 42 and power source 22 is selectively closed when the actuator 44 is pressed, thereby powering the valve 42 to move to an open position. While any of an assortment of different flow-controlling devices may be employed, it may be desirable that the valve 42 of FIG. 1 be an electromagnetic solenoid valve or a manual spool valve. The liquid pump 40 can also be electrically connected to and powered by the power source 22. In accord with the illustrated architecture, the pump 40 may be a centrifugal pump or a solenoid pump. It is also envisioned that the pump 40 may be eliminated from the system 12 and, if desired, the flow control system 36 may be a gravity-fed system. For instance, one or more mechanically actuated or electrically actuated valves may be fluidly coupled with outlet ports of the container(s) 34, 52; when opened, the valve(s) may allow fluid to flow under the force of gravity to the distributor 38.

[0032]With continuing reference to FIG. 1, the fluid distributor 38 may include one or more distributor outlets 48 for ejecting cleaning fluid onto a surface being cleaned. The distributor outlet(s) 48 may be packaged within the extraction cleaner 10 system to deliver fluid directly onto the surface or indirectly by delivering fluid onto or through the agitator 26. The distributor outlet(s) 48 may take on any suitable structure, such as a nozzle or spray tip or a distributed arrangement of distributor outlets 48. As illustrated in FIG. 1, for example, the distributor outlet 48 includes multiple spray tips that dispense cleaning fluid to a surface. If desired, the cleaning tool 30 may optionally include an auxiliary distributor outlet (not shown) that is coupled with the fluid delivery system 12. While FIG. 1 may be considered a schematic illustration of an upright deep cleaner (UDC), select features from this Figure may be adapted for incorporation into other extraction cleaner configurations, including portable deep cleaners (PDC) of the handheld and pod style.

[0033]An optional fluid heater device 50 may be fluidly interposed between the fluid container 34 and the fluid distributor 38 to selectively heat the cleaning fluid prior to the liquid pump 40 delivering the cleaning fluid through the distributor outlets 48 to the surface. According to the example illustrated in FIG. 1, an in-line electronic heater 50 is located downstream from the fluid container 34 and upstream of the pump 40. In yet another example, the cleaning fluid can be heated using exhaust air from a motor-cooling exhaust pathway for the suction source 18.

[0034]Fluid delivery system 12 of FIG. 1 may employ a single or multiple vessels for storing and dispensing a cleaning fluid or the pre-mixed components of a cleaning fluid mixture. For example, a first fluid container 34 may store water and a second fluid container 52 may store a cleaning detergent or additive. By way of example, and not limitation, the two containers 34, 52 may be defined by a supply tank and a collapsible bladder. In one configuration, the fluid container 34 may be a bladder that is stored within the recovery container 20. Alternatively, a single fluid container may be fabricated with multiple internal chambers for storing a variety of different liquids. The cleaning fluid in either container 34, 52 can include, but is not limited to, water or a mixture including water and one or more treating agents. These treating agents may include, but are not limited to, detergents, odor eliminators, sanitizers, stain removers, odor removers, deodorizers, fragrances, or any combination thereof.

[0035]For fluid delivery system architectures employing multiple containers 34, 52, the flow control system 36 may be equipped with a mixing system 54 operable to control a composition of the cleaning fluid that is delivered to the surface through the distributor 38. The cleaning fluid composition may be determined by a controlled ratio of cleaning fluids mixed together by the mixing system. As shown in FIG. 1, the mixing system 54 is typified by a mixing manifold 56 that selectively receives fluid from one or both of the fluid containers 34, 52. A mixing valve 58 is fluidly coupled with an outlet port of the second container 52; when the mixing valve 58 is opened, the cleaning fluid component from the second container 52 will flow to the mixing manifold 56. The composition of the cleaning fluid that is delivered to the surface can be selected by controlling the valve flow characteristics—timing, frequency, and length—of the mixing valve 58.

[0036]In operation, the extraction cleaner 10 of FIG. 1 may be prepared for use by electrically connecting the extraction cleaner 10 to the power source 22 and by filling one or both fluid containers 34, 52 with a cleaning fluid or cleaning fluid components. Metered amounts of cleaning fluid may be selectively delivered to a chosen surface being cleaned via the fluid delivery system 12 by user-activation of the actuator 44. If desired, the extraction cleaner 10 may be concurrently moved back and forth over the chosen surface. The agitator 26 can simultaneously agitate the cleaning fluid into the chosen surface. During operation of the fluid recovery system 14, the extraction cleaner 10 draws in fluid and debris-laden working air through the suction nozzle 16 or cleaning tool 30, depending on the position of the diverter assembly 32. The working air is pulled into the downstream recovery container 20 where the liquid and debris are substantially separated from the working air. The airstream then passes through the suction source 18 prior to being exhausted from the extraction cleaner 10. The recovery container 20 can be periodically emptied of collected fluid, dirt, and other debris. Additional details of extraction cleaners, including their constituent parts, architectures, and uses, are disclosed in U.S. Pat. Nos. 7,784,148, 9,560,948, 10,188,252, 10,588,476, and 10,624,515, all of which are incorporated herein by reference in their respective entireties and for all purposes.

[0037]Turning next to FIGS. 2-5, there is shown a representative example of a multi-roller cleaning head 100 for a vacuum-based extraction cleaner, such as surface cleaning system 10 of FIG. 1. Although shown as a wheeled base assembly (or “foot) of an upright or stick-type vacuum cleaner, it should be appreciated that the linearly adjustable floating roller concepts described below with respect the surface cleaning head 100 are similarly applicable to other cleaner heads and other extraction cleaner configurations. The cleaning head 100 is portrayed in FIG. 2 with a tripartite main (base) housing 102 that is generally composed of a nozzle housing shell (or forward upper shell) 104 defining a front end of the cleaning head 100, a connector housing shell (or rearward upper shell) 106 rigidly mounted to the nozzle housing shell 104 and defining a rear end of the cleaning head 100, and a subjacent base plate (or lower housing shell) 108 that is located underneath and rigidly secured to both the nozzle housing shell 104 and connector housing shell 106. The three shell 104, 106, 108 segments of the main housing 102 cooperatively define an internal vacuum chamber 101 (FIG. 3) inside the housing 102. An optional pair of (first and second) cover plates 110 and 112 may be secured to port-side and starboard-side (first and second) flanks, respectively, of the main housing 102. It is envisioned that the main housing 102 may include greater or fewer than the three primary housing shell segments 104, 106, 108 and two optional cover plates 110, 112 without departing from the intended scope of this disclosure.

[0038]An ankle dock 114 of the connector housing shell 106 releasably couples with a leg knuckle joint 116 of an upright vacuum cleaner body 122 via a spring-biased locking trigger 118. When the leg knuckle joint 116 is received in and locked to the ankle dock 114, a connector port 103 of the connector housing shell 106 receives therethrough a terminal (bottom) end of a vacuum hose 120 (representative of a “fluid conduit”). The vacuum hose 120, in turn, is torqued into or otherwise physically mated with an aft-facing open end of an integral hose duct 105 of the nozzle housing shell 104 to thereby fluidly connect the surface cleaning head 100 to a debris canister and motor/fan assembly (e.g., suction source 18 and recovery container 20 of FIG. 1) of the surface cleaning system. The connector port 103 and, thus, the vacuum hose 120 fluidly connect via the hose duct 105 and internal vacuum chamber 101 to a nozzle inlet 107 of the nozzle housing shell 104. As the cleaning head 100 is moved across a target surface, dirt and debris from the target surface is ingested into the cleaning head 100 through this nozzle inlet 107; the ingested dirt/debris passes from the nozzle inlet 107, through the vacuum chamber 101 and hose duct 105, and out of the cleaning head 100 through the connector port 103 and hose 120.

[0039]It may be desirable, e.g., for simplicity of design and case of manufacture, that the nozzle housing shell 104, connector housing shell 106, and base plate 108 each be fabricated from a rigid polymeric material as a single-piece, unitary structure (e.g., via injection molding, vacuum molding, multi-shot molding, etc.). For one-piece designs, a forward half of the nozzle housing shell 104 may be constructed as an integral roller housing 109 that contains both a main roller compartment 111, which adjoins the vacuum chamber 101, and a leading roller compartment 113, which is forward of and fluidly coupled to the main roller compartment 111. When the main housing 102 is fully assembled, the roller housing 104 and the base plate 108 may cooperatively define the nozzle inlet 107, whereas the nozzle housing's hose duct 105 and the connector housing shell 106 may cooperatively define the connector port 103. As yet another option, a forward-most end of the base plate 108 may define an unobstructed roller window 115 (FIG. 2) through which larger pieces of debris may enter the roller compartment 113 and, thus, the main housing 102.

[0040]With continuing reference to FIGS. 2-5, the surface cleaning head 100 is a multi-roller design with a linearly fixed main roller 124 that is located aft of a linearly adjustable lead roller 126. As best seen in FIGS. 3 and 4, the main (first) roller 124 is rotatably mounted inside the main roller compartment 111 of the nozzle housing shell 104, located between the nozzle inlet 107 and the connector port 103/hose duct 105. The leading (second) roller 126 is rotatably mounted to the leading roller compartment 113 of the nozzle housing shell 104, oriented substantially parallel to and forward of the main roller 124. Unlike many conventional multi-roller cleaning head designs, both of the rollers 124, 126 of the cleaning head 100 are shown packaged inside the same, one-piece roller housing 109. As another non-limiting point of demarcation over existing multi-roller cleaning head designs, the fixed main roller 124 may be a surface-agitating brushroll that includes multiple brush-bristle tufts 128, whereas the floating lead roller 126 may be a soft-padded roller, i.e., sans brushes, bristles, nubs, etc., to optimize cleaning head suction pressure. In another example, a roller motor (e.g., electric motor 230 of FIG. 6), which may be packaged within or otherwise operatively attached to the main housing 102, is drivingly connected to and operable to selectively rotate the main roller 124 but not the lead roller 126.

[0041]To facilitate the ingestion of both large and small debris without compromising the cleaning head's suction pressure, the lead roller 126 may be a compressible, reduced-diameter (“small and fluffy”) sealing roller located at the front end of the main housing 102. Contrastingly, the main roller 124 may be a brushed, large-diameter cleaning roller that is located aft of the lead roller 126, interposed between the vacuum chamber 101 and nozzle inlet 107. The lead roller 126 may be designed to “float” such that it: (1) automatically lifts, under the force of the debris, when contacting and rolling over large debris; and (2) automatically drops, under the force of gravity, back into flush contact with the target surface after clearing the large debris to maintain continuous suction pressure within the vacuum chamber 101. According to the example illustrated in FIG. 4, the main roller 124 has a first (roller) diameter D_R1 that is larger than a second (roller) diameter D_R2 of the lead roller 126. When including the main roller's bristle tufts 128, for example, the main roller's diameter D_R1 is two to three times larger than the lead roller's diameter D_R2. The smaller diameter D_R2 of the floating lead roller 126 allows for a relatively large vertical displacement of the lead roller 126 without requiring a significant increase in packaging space within the cleaning head's main housing 102. It is envisioned that some applications may employ a lead roller with a diameter that is larger than that of the main roller.

[0042]With reference to FIG. 5, the representative lead roller 126 is portrayed as a soft “padded” roller that may be characterized by a lack of bristles, nubs, flexible flaps, etc., such that the outermost periphery of the roller 126 sits flush against and thereby seals to the target surface. The lead roller 126 may include an elongated and hollow roller shaft 128 with a tubular and compressible roller sheath 130 that is pressed onto and covers the roller shaft 128. A pair of (first and second) friction wheels 132 and 134 are rigidly secured, e.g., via splined or keyed engagement, to opposing (first and second) longitudinal ends, respectively, of the roller shaft 128. The outer circumference of each friction wheel 132, 134 may be covered with surface-engaging teeth, treads, pads, or other friction-increasing feature. A pair of (first and second) cylindrical mounting pins 136 and 138 (also referred to herein as “bearings”) is each integrally formed with and projects axially from an outboard face of a respective one of the friction wheels 132, 134. To rotate the lead roller 126, the friction wheels 132, 134 are driven by frictional forces generated by a target surface when a user pushes or pulls the surface cleaning head 100 across the target surface (i.e., without a driving torque input by an electric motor). The mounting pins 136, 138 may be configured as plane bearings or roller bearings to facilitate the smooth rotation of the lead roller 126.

[0043]Passive linear adjustment of the floating roller's vertical height may be enabled by sliding engagement of the lead roller 126 with the main housing 102. By way of non-limiting example, FIG. 5 shows a pair of (first and second) linear pin slot 117 and 119 that each extends through a respective mounting wall 121 and 123 inside the leading roller compartment 113 of the cleaning head's nozzle housing shell 104. Each of the lead roller's mounting pins 136, 138 slidably mounts inside a respective linear pin slot 117 and 119 such that the lead roller 126 freely floats, e.g., in a reciprocating linear motion, within the main housing 102. By using this free-floating arrangement, rather than a spring-biased, pivot-mounted roller support housing used in other multi-roller cleaning head designs, the lead roller 124 slides unobstructed within the linear pin slots 117, 119 (e.g., up and down in FIG. 5) between a lowered position (FIG. 3) and a raised position (FIG. 4). The lead roller 126 is thus biased by gravity from the raised position to the lowered position. i.e., without the use of a return spring or other biasing mechanism.

[0044]Turning next to FIGS. 6 and 7, there is shown a non-limiting example of a roller drivetrain system 200 for transmitting driving torque to a floating secondary roller in a multi-roller cleaning head. Although differing in appearance, it is envisioned that any of the features and options described above with respect to the multi-roller cleaning head 100 of FIGS. 2-5 may be incorporated, singly and collectively, into the multi-roller drivetrain system 200 configuration of FIGS. 6 and 7, and vice versa. As a non-limiting point of similarity, the drivetrain system 200—like the cleaning head 100—includes a fixed-height main (first) roller 224 that is located aft of an adjustable-height lead (second) roller 226. Moreover, the main roller 224 may be a brushed, large-diameter cleaning roller that is parallel to and space from the lead roller 226, whereas the lead roller 226 may be a compressible, reduced-diameter padded roller that sits flush against a target surface. This multi-roller arrangement may help to maintain the vacuum pressure inside the cleaning head's internal vacuum chamber while also helping the main roller 224 to pick-up both fine dust and large debris.

[0045]The torque-transmitting roller drivetrain system 200 is portrayed in FIGS. 6 and 7 as a belt-drive type drivetrain with a central axle 202 that is rotatably attached to a cleaner head housing (e.g., main housing 102 of FIG. 2) such that the axle 202 is substantially parallel to and interposed between the main and lead rollers 224, 226. The central axle 202 carries and thereby rotates in unison with a pair of (first and second) axle wheels 204 and 206 (e.g., the term “wheel” may reference a gear, sheave, sprocket, etc.). The main (first) axle wheel 204 drivingly connects via a main (first) continuous belt 208 to a main (first) roller wheel 210 of the main roller 224. In the same vein, the lead (second) axle wheel 206 drivingly connects via a lead (second) belt 212 to a lead (second) roller wheel 214 of the lead roller 226.

[0046]In accord with the example illustrated in FIG. 6, the main axle wheel 204 has a main (first) axle wheel diameter D_AW1, and the lead axle wheel 206 has a lead (second) axle wheel diameter D_AW2 that is smaller than the first axle wheel's diameter D_AW1. Moreover, the main roller wheel 210 has a main (first) roller wheel diameter D_RW1 that is smaller than the wheel diameter D_AW1 of the main axle wheel 204 and larger than the wheel diameter D_AW2 of the lead axle wheel 206. Comparatively, the lead roller wheel 214 has a lead (second) roller wheel diameter D_RW2 that is larger than the lead axle wheel's diameter D_AW2 yet smaller than the main axle wheel's diameter D_AW1. Motor torque output by an electric roller motor 230 may be transmitted to the main roller 224, from the main roller 224 through the main roller wheel 210, belt 208, and axle wheel 204 to the central axle 202. The central axle 202 then transmits this motor torque through the lead axle wheel 206 and belt 212, through the lead roller wheel 214 to the lead roller 226. It is envisioned that the individual and relative wheel diameters of the torque-transmitting wheels may be varied from what is shown in FIG. 6.

[0047]To rotatably and slidably mount the central axle 202 and lead roller 226 to the cleaning head's main housing, a mounting wall or plate 216 (FIG. 7) is attached to or integrally formed with the main housing and operatively supports both the axle 202 and the roller 226. The mounting wall/plate 216 includes a pair of (first and second) axle slots 215 and 217; the central (first) axle slot 215 may be arcuate (e.g., the radial center point of the slot 215 arc is the rotational axis of the main roller 210), and the lead (second) axle slot 217 may be linear. The central axle 202 is slidably mounted inside the central axle slot 215 to translate along an arcuate path DPI, whereas the lead roller 226 is slidably mounted inside the lead axle slot 217 to translate along a rectilinear path D_P2. The central slot 215 may be vertically and horizontally offset from the lead slot 217 such that the central axle 202 is vertically and horizontally offset from the lead roller 226. The second rectilinear path D_P2 of the lead roller 226 may be obliquely angled relative to the first rectilinear path D_P1 of the central axle 202 (e.g., angle of about 20° to) 30°. The main roller 224 may be pivotably attached to the central axle 202 via a main (first) pair of control arms or brackets 218, whereas the lead roller 226 may be pivotably attached to the central axle 202 via a lead (second) pair of control arms or brackets 220. The main control arms/brackets 218 may be angled relative to the lead pair of control arms/brackets 220, e.g., at an offset angle α of about 100° to 130°. With this arrangement, large debris may pass under one end of the lead roller 226 and raise only that one end of the lead roller 226; at the same time, the other end of the lead roller 226 may remain at the first (lowered) position without causing the lead roller 226 to function improperly.

[0074]While some representative modes have been described in detail above, various alternative designs may exist for practicing the present teachings defined in the appended claims. Those skilled in the art will recognize that modifications may be made to the disclosed embodiments without departing from the scope of the subject disclosure. Moreover, the present concepts expressly include combinations and sub-combinations of the described elements and features. The detailed description and the drawings are supportive and descriptive of the present teachings, with the scope of the present teachings defined solely by the claims.