Surface cleaner system, surface cleaning head and method of assembling same

Abstract

Surface cleaning systems, surface cleaning heads, and methods of assembling the same are presented herein. A surface cleaning head includes a main housing having first and second linear pin slots, a nozzle inlet to draw debris from a surface, and a connector port coupled with a fluid conduit to fluidly connect the cleaning head to a suction device. A first roller is rotatably attached to the main housing between the nozzle inlet and the connector port. A second roller is rotatably mounted to the main housing parallel to the first roller. The second roller includes a roller shaft having first and second mounting pins protruding from first and second ends of the roller shaft, respectively, and slidably mounted in the first and second linear pin grooves, respectively, such that the second roller floats in the main housing.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to surface cleaning systems that generate suction to remove debris from a surface. In particular, aspects of the present disclosure relate to a manually operated vacuum cleaner having a multi-roll cleaning head. BACKGROUND

[0002] Conventional vacuum cleaners are electrically powered pneumatic devices that generate a gas pressure differential to clean hard surfaces, such as tile and wood flooring, as well as soft surfaces, such as carpet and upholstery. While traditionally built as "dry" type cleaning devices limited to the removal of dirt, dust, and solid fluid debris, some surface cleaning vacuum cleaners are modified as "wet" type recovery systems that are also capable of extracting stains and other liquids from a target surface to be cleaned. Vacuum cleaners generally include a suction nozzle that is moved over a target surface to draw in debris, a recovery container for storing removed debris, and a fluid conduit that fluidly connects the suction nozzle to the recovery container. Thus, air containing debris is drawn from the target surface through the suction nozzle and connected fluid conduit and into the recovery container for storage and subsequent disposal. Many vacuum cleaners use an agitator to loosen debris on the target surface so that it is more easily drawn into the suction nozzle. In most cases, the agitator is a single motor-driven brush roll that rotates adjacent the suction nozzle within a base assembly (or "cleaning head"). Vacuum cleaners can also include an auxiliary agitator for providing additional agitation to the target surface. One type of auxiliary agitator is a secondary "lead" brush roll that is positioned forward of a primary "trail" brush roll and serves to sweep dirt and debris into the suction path of the suction nozzle. SUMMARY

[0003] Presented herein are multi-roll surface cleaning heads having a linearly adjustable floating roll, methods of manufacturing such surface cleaning heads and methods of using the same, and vacuum-based surface cleaning systems having such cleaning heads. In a non-limiting example, a multi-roll surface cleaning head includes a motor-driven primary brush roll having a primary roll diameter, and a floating secondary roll positioned forward of the primary brush roll and having a secondary roll diameter that is less than the primary roll diameter. To facilitate the removal of large debris, the floating secondary roll has a roll height that is dynamically adjustable, such that it automatically raises when passing over large debris, and subsequently lowers under the influence of gravity when passing over small debris to maintain suction pressure. The floating roll can be a soft-pad bearing roll, i.e., without brushes, bristles, bumps, etc., to optimize the cleaning head suction pressure. For a friction-driven configuration, the rotation of the floating secondary roll is driven by frictional forces generated by the target surface. In this case, planar bearings can be installed at opposite ends of the floating secondary roll to facilitate smooth rotation of the secondary roll. Each of these bearings can be slidably mounted in a corresponding linear slot that is recessed or extends through a mounting bracket or plate of the cleaning head main housing.

[0004] For a motor-driven configuration, the drive torque of the roller motor is transmitted from the primary roller to the secondary roller via a belt drive power transmission system. In this case, the belt drive system can include a central axle that supports both a primary gear / pulley that is drivingly connected to a primary gear / pulley of the primary roller via a first belt and a secondary gear / pulley that is drivingly connected to a secondary gear / pulley of the secondary roller via a second belt. To optimize mechanical advantage, a first diameter of the first gear / pulley can be greater than a second diameter of the second gear / pulley. Further, a third diameter of the primary gear / pulley can be less than the first diameter of the first gear / pulley, and a fourth diameter of the secondary gear / pulley can be greater than the second diameter of the second gear / pulley and less than the first diameter of the first gear / pulley. To facilitate floating of the secondary (“guide” or “lead”) roller, an axle of the lead axle of the lead roller can 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 can 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 can be tilted at an oblique angle relative to the first set of linear slots.

[0005] Aspects of the present disclosure relate to a multi-roller cleaning head with linearly adjustable floating rollers for a vacuum-based surface cleaning system. As used herein, the terms “surface cleaning system” and “surface cleaner” and “extractor cleaner” - including variants and permutations thereof - can be used interchangeably and synonymously to include any related vacuum-based cleaning system, including wet or dry extraction types in wired and wireless configurations of upright, canister, stick, hand-carried, and pod form factors, as some non-limiting examples. In an example, a surface cleaning head for a surface cleaning system is presented, the surface cleaning system including a recovery tank, a suction device fluidly connected to the recovery tank via a fluid conduit, and other original or aftermarket devices.

[0006] Continuing the preceding example, the surface cleaning head includes a primary (chassis) housing with a pair of linear pin slots, a suction nozzle inlet through which debris is drawn from a target surface, and a connector port fluidly connected to the suction nozzle inlet and operatively coupled with the fluid conduit of the cleaning system, thereby fluidly connecting the cleaning head to the suction device. A first (primary) roller is rotatably attached to the primary housing, between the suction nozzle inlet and the connector port. A roller motor (e.g., a 2-stage direct current (DC) electric motor) is also attached to the primary housing, the roller motor drivingly connected to the first roller and operable to selectively rotate the first roller. A second (secondary) roller is also rotatably attached to the primary housing, oriented substantially parallel to the first roller. The second roller includes an elongated roller axle having a pair of mounting pins protruding from opposite ends of the roller axle. Each mounting pin is slidably mounted in a respective one of the linear pin slots of the housing, such that the second roller is free to float (e.g., in a reciprocating linear motion) within the primary housing.

[0007] Further aspects of the present disclosure relate to an extractor cleaner system equipped with a multi-roll surface cleaning head having a linearly adjustable floating roller. In an example, a surface cleaning system for removing dirt and debris from a target surface is presented. The surface cleaning system includes a recovery container that is detachably attached to a main cleaner body and stores debris extracted from the target surface therein. A suction device is also attached to the cleaner body, the suction device 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 foregoing surface cleaning system further includes a surface cleaning head movably mounted to, integrally formed with, or otherwise attached to the cleaner body. The surface cleaning head includes a main housing having a pair of linear pin slots, a suction nozzle inlet that draws debris from the target surface, and a connector port fluidly connected to the suction nozzle inlet and coupled to the hose, thereby fluidly connecting the surface cleaning head to the recovery container and the suction device. A main (trailing) roller is rotatably attached to the main housing, interposed between the suction nozzle inlet and the connector port. A roller motor is also attached to the main housing, the roller motor drivingly connected to the main roller 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. The auxiliary roller includes a roller shaft having a pair of mounting pins protruding from opposite longitudinal ends of the roller shaft. Each mounting pin is slidably mounted in a respective one of the linear pin slots of the main housing, such that the auxiliary roller floats within the main housing. With this arrangement, the auxiliary roller unimpededly slides along a linear path between a lowered position and a raised position, such that the auxiliary roller is biased from the raised position to the lowered position under the force of gravity, i.e., without the use of a return spring or other biasing mechanism.

[0009] Aspects of the present disclosure also relate to methods of manufacturing any of the surface cleaning systems, cleaner heads, roller drive systems, etc. disclosed herein, and methods of operating the same. In an example, a method of assembling a surface cleaning head of a surface cleaning system is presented. The representative method includes, in any order and in any combination with the options and features disclosed above and below: receiving a main housing of the surface cleaning head, the main housing having a first linear pin slot and a second linear pin slot, a suction nozzle inlet configured to suction debris from a target surface, and a connector port fluidly connected to the suction nozzle inlet; coupling the connector port with a fluid conduit of the surface cleaning system, thereby fluidly connecting the surface cleaning head to a suction device; rotatably attaching a first roller to the main housing such that the first roller is interposed between the suction 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 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 having a first mounting pin and a second mounting pin protruding from opposite first and second ends of the roller shaft and slidably mounted in the first and second linear pin slots, respectively, such that the second roller is floating in the main housing.

[0010] For any of the disclosed systems, methods, and apparatuses, the second roller can slide unimpeded within the linear pin slots of the main housing from a first (lowered) position to a second (raised) position and back to the lowered position. In this case, the second roller can be biased from the raised position to the lowered position by gravity without a spring force of a spring (e.g., a coil spring, a leaf spring, an air spring, etc.). As another option, the main housing of the cleaner head can include a suction nozzle housing shell at least partially defining the suction nozzle inlet and a connector housing shell mounted to the suction nozzle housing shell and at least partially defining the connector port. In this case, both the first and second rollers are rotatably mounted inside the suction nozzle housing shell. The suction nozzle housing shell can be a single-piece structure that includes an integral roller housing having a main roller compartment in which the first roller is mounted and a front guide roller compartment in which the second roller is mounted. The main housing of the cleaner head can also include a single-piece chassis rigidly attached to both the connector housing shell and the suction nozzle housing shell. Once attached, the chassis and the roller housing can collectively define the suction nozzle inlet, while the suction nozzle housing shell and the connector housing shell can collectively define the connector port.

[0011] For any of the disclosed systems, methods, and apparatuses, the first roller can have a first roller diameter, and the second roller can have a second roller diameter that is less than the first roller diameter. Alternatively, the first roller can be a brush roller comprising a plurality of bristle tufts, and the second roller can be a soft-pad belt roller without bristles, for example, to maintain suction pressure at the mouth of the suction nozzle. It can be desirable for the second roller to be not drivingly engaged with the motor, so that the second roller is frictionally driven by frictional forces generated by the target surface as the cleaning head is caused to move over the target surface. In this case, the second roller can comprise a pair of friction wheels, each rigidly fixed to a respective end of the roller axle. Each of the mounting pins of the second roller can be integrally formed with and protrude axially outwardly from a respective one of the friction wheels.

[0012] For any of the disclosed systems, methods, and apparatuses, the surface cleaning head can further comprise a belt drive system having a central axle attached to the main housing such that the central axle is parallel to and interposed between the first and second rollers. The central axle supports a pair of torque-transferring "wheels" (e.g., gears, pulleys, sprockets, etc.) including a first (axle) wheel drivingly connected to a first (roller) wheel of the first roller via a first belt, and a second (axle) wheel drivingly connected to a second (roller) wheel of the second roller via a second belt. The first and second axle wheels can rotate in unison with each other and in unison with the central axle. Likewise, the first roller wheel can rotate in unison with the first roller, and the second roller wheel can rotate in unison with the second roller. In this case, the first axle wheel can have a first axle diameter, the second axle wheel can have a second axle diameter that is less than the first axle diameter, the first roller wheel can have a first roller diameter that is less than the first axle diameter, and the second roller wheel can have a second roller diameter that is less than the second axle diameter.

[0013] For any of the disclosed systems, methods, and apparatuses, the main housing can further comprise a pair of linear axle slots within which the central axle is slidably mounted to translate along a first linear path. In this case, the second roller can translate along a second linear path that is inclined (e.g., offset by an angle of about 20 o to 30 o ) relative to the first linear path. Alternatively, the first roller can be pivotally attached to the central axle via a first pair of control arms, and the second roller can be pivotally attached to the central axle via a second pair of control arms. In this case, the first and second rollers can share substantially the same diameter, while the first roller can be bristled and the second roller can be covered with a compressible "fluffy" material. It can be desirable for the first and second axle wheels and the first and second roller wheels to be sprockets or gears, and for the interconnecting first and second belts to be toothed belts.

[0014] The above summary of the disclosure does not represent each and every embodiment or aspect of the present disclosure. Rather, the above summary merely provides an illustration of some of the novel concepts and features set forth herein. The above features and advantages, and other features and advantages of the present disclosure are readily apparent from the following detailed description of the best modes for carrying out the present disclosure when taken in connection with the accompanying drawings and the appended claims. Moreover, the present disclosure contemplates that the foregoing summary and the following detailed description thereto are intended to be included within the scope of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a schematic view of a representative vacuum-based surface cleaning system in accordance with aspects of the present disclosure, which can practice the novel features of the present disclosure.

[0016] Figure 2 is an enlarged perspective view of a representative surface cleaning system having a representative multi-roller cleaning head with linearly adjustable floating guide rollers in accordance with aspects of the present disclosure.

[0017] Figure 3 is a perspective view of the representative multi-roller cleaning head of Figure 2 illustrating the floating guide rollers in a first (lowered) position.

[0018] Figure 4 is a perspective view of the representative multi-roller cleaning head of Figure 2 illustrating the floating guide rollers lifted to a second (raised) position.

[0019] Figure 5 is a perspective view of the representative multi-roller cleaning head of Figure 2 illustrating the floating guide rollers slidably mounted within linear pin slots inside the main housing of the cleaning head.

[0020] Figure 6 is a perspective view of a representative torque transfer roller drive system of a multi-roller cleaning head of a vacuum-based surface cleaning system in accordance with aspects of the present disclosure.

[0021] Figure 7 is a perspective view of a representative roller drive system of Figure 6 illustrated with the central wheel axle and the front idler axle slidably mounted within respective sets of slots of the mounting plate.

[0022] The present disclosure is susceptible 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 the present disclosure are not limited to the particular configurations described herein and / or shown in the drawings. Instead, the present disclosure is to cover all modifications, equivalents, combinations, permutations, and alternatives falling within the scope of the disclosure as encompassed by the appended claims. DETAILED DESCRIPTION

[0023] The present application allows for a great variety of embodiments. Representative embodiments of the present disclosure are shown in the drawings and will be described in detail below, it being understood that these embodiments are provided as examples of the disclosed principles and are not intended to limit the broad aspects of the present disclosure. In this regard, elements and limitations appearing in the specification and / or drawings that are not explicitly set forth in the claims should not be necessarily construed as limiting the disclosure. Rather, such elements and limitations are to be considered as having been presented as examples of the principles underlying the present disclosure, and the scope of the disclosure is to be determined solely by the appended claims.

[0024] Additionally, unless explicitly stated otherwise, singular includes plural, and plural includes singular; "and" and "or" shall be both conjunctive and disjunctive; the words "any" and "all" mean "any and all"; and the words "comprise(s)", "contain(s)", "include(s)", "have(s)", "holding(s)", and the like can mean "including but not limited to". Moreover, the approximating words such as "about", "almost", "essentially", "substantially", "approximately", and the like, can be used in this document to mean "in a range of 0-5%" or "within acceptable manufacturing tolerances" or "within 10% of the value being described", or any like meaning, as would be understood by one of ordinary skill in the art. Finally, directional adjectives and adverbs, such as front, back, left, right, anterior, posterior, vertical, horizontal, forward, rearward, upward, downward, etc., can be relative to a surface cleaning device that is operatively oriented for cleaning a horizontal target surface.

[0025] Reference will now be made to the drawings wherein like numerals refer to like components throughout the several figures, and Figure 1A schematic view of a representative surface cleaning system is shown, indicated generally at 10 and depicted herein for purposes of discussion as a manually operated upright vacuum cleaner. The surface cleaning system 10 shown (also referred to herein as a "surface cleaner" or "extractor cleaner") is merely an exemplary application in which aspects of the present disclosure can be practiced. Likewise, the use of the present concepts in a guide roller in a dual roller cleaning head should be understood as an exemplary application of the novel concepts disclosed herein. Thus, it will be understood that aspects and features of the present disclosure can be used in other cleaning head configurations and in any logically relevant type of surface cleaning system. Moreover, only select components of the surface cleaning system and multi-roller cleaning head are shown and described in detail below. Nonetheless, the surface cleaning systems and cleaning heads discussed herein can include many additional and alternative features for performing the various methods and functions of the present disclosure.

[0026] Figure 1 Various functional subsystems of a vacuum-based extractor cleaning tool in the form of a surface cleaning system 10 are shown. These functional subsystems can be arranged in any desired configuration, including upright extractor devices, canister extractor devices, pod extractor devices, hand-carried extractor devices, autonomous and robotic cleaning devices, and commercial cleaners. For example, any of the multi-roller surface cleaning heads described herein (such as the multi-roller surface cleaning head presented in Figures 2 to 7 may be incorporated or retrofitted to include any of the relevant features of the surface cleaning system 10 shown in Figure 1 , and vice versa. For example, a multi-roller surface cleaning head having a linearly adjustable floating guide roller can be adapted to be detachably coupled to, permanently affixed to, or integrally formed with a flexible vacuum cleaner hose or main vacuum cleaner body that can form part of a suction nozzle and suction source in a wheeled or load-bearing base of an upright, canister, hand-carried, or pod extractor device.

[0027] Figure 1The extraction cleaner 10 can be a two-part architecture having a fluid delivery system 12 that stores and selectively dispenses cleaning fluid to a surface being cleaned, and a fluid recovery system 14 that removes used cleaning fluid and debris from the surface being cleaned and stores the recovered cleaning fluid and debris. In this case, the fluid recovery system 14 is shown to consist of an upstream end suction nozzle 16, a downstream end vacuum generating suction source 18, and an optional waste storage recovery container 20. The suction source 18, which can be an electrically powered fan, positive displacement, or centrifugal rotor powered assembly, is fluidly connected to the suction nozzle 16 and generates a working airflow to draw liquid and debris into the recovery system 14 when desired. The recovery container 20, which can be interposed between the suction nozzle 16 and the suction source 18, separates and collects liquid and debris from the working airflow for later disposal. A separator 21 can be enclosed within a portion of the recovery container 20 for separating liquid and entrained debris from the working airflow. It should be appreciated that the fluid delivery system 12 can be entirely omitted from the surface cleaning system 10, e.g., for dry cleaning applications. Figure 1

[0028] Continuing the discussion of a representative extraction cleaner 10 system in Figure 1 , the suction source 18 can be any suitable electromechanical device that generates a vacuum, which is electrically coupled or couplable to a power source 22, such as a rechargeable battery or an electrical outlet. A power switch 24, which can be located between the suction source 18 and the power source 22, can be selectively actuated by a user to activate the suction source 18. The suction nozzle 16, through which dirt, debris, used cleaning solution, etc. is drawn, can be integrated into a base, tool, or cleaning head, and can be adapted to move over a target surface being cleaned. An optional agitator 26 can be positioned adjacent to the suction nozzle 16 to disturb the surface being cleaned so that debris is broken up and more easily drawn into the suction nozzle 16. Some non-limiting examples of agitators include horizontally oriented rotating brush rolls, vertically oriented rotating brush rolls, fixed brushes, arrays of flexible protrusions, etc.

[0029] The extraction cleaner 10 can be operatively interfaced with any of a variety of interchangeable accessories and tools to facilitate different cleaning tasks. For example, in Figure 1 , an accessory hose 28 can selectively fluidly couple the suction source 18 to an accessory tool or cleaning accessory 30 having a separate suction inlet, such as an extension wand, upholstery tool, dusting brush, etc. In some embodiments, a diverter valve assembly 32 or other diverter 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 can also employ a fluid dispenser Figure 1 (not shown in) that fluidly connects the fluid delivery system 12 with the tool / accessory 30 to selectively expel cleaning fluid therefrom. ​

[0030] The fluid delivery system 12 of the extractable cleaner can be comprised of a refillable or interchangeable (first) fluid container 34 located at the upstream end of the system 12, a fluid dispenser 38 located at the downstream end of the system 12 to dispense the liquid, and a flow control system 36 between the container 34 and the dispenser 38 to regulate the flow of the liquid. The fluid container 34 stores and selectively dispenses cleaning fluid therefrom. The cleaning fluid can include one or more of any suitable cleaning fluid, such as water, chemical composition, concentrated detergent, dilute detergent, and the like, and mixtures thereof. The flow control system 36 controls the transfer of the cleaning fluid from the container 34 to the dispenser 38. In the illustrated configuration, the flow control system 36 employs a one-way liquid pump 40 to pressurize the fluid delivery system 12 and one or more flow control valves 42 to control the delivery of the cleaning fluid to the dispenser 38.

[0031] An actuator 44, which can be a trigger or lever that can be manually operated in nature, can be provided to activate the flow control system 36 and dispense fluid to and through the dispenser 38. For a normally closed valve assembly, the actuator 44 can be operatively coupled to the valve 42 such that pressing the actuator 44 will open the valve 42. The valve 42 can be an electrically actuated valve device such that when the actuator 44 is depressed, an electrical switch 46 located between the valve 42 and the power source 22 is selectively closed, thereby energizing the valve 42 to move to an open position. Although any of a variety of different flow control devices can be employed, it can be desirable that Figure 1 the valve 42 is a solenoid valve or a manually operated spool valve. The liquid pump 40 can also be electrically connected to and powered by the power source 22. In accordance with the illustrated architecture, the pump 40 can be a centrifugal pump or a solenoid pump. It is also contemplated that the pump 40 can be eliminated from the system 12 and, if desired, the flow control system 36 can be a gravity feed system. For example, one or more mechanically or electrically actuated valves can be fluidly coupled with the outlet port of the container 34, 52; when opened, the valves can allow fluid to flow under the force of gravity to the dispenser 38.

[0032] With continued reference to Figure 1 the fluid dispenser 38 can include one or more dispenser outlets 48 for spraying cleaning fluid onto the surface being cleaned. The dispenser outlets 48 can be enclosed within the extractable cleaner 10 system to deliver fluid directly onto the surface or indirectly through delivery to and through the agitator 26. The dispenser outlets 48 can take any suitable structure, such as a nozzle or nozzle tip or a distributed arrangement of dispenser outlets 48. As shown, for example, the dispenser outlets 48 include a plurality of nozzle tips to dispense cleaning fluid onto the surface. If desired, the cleaning tool 30 can optionally include an auxiliary dispenser outlet (not shown) coupled with the fluid delivery system 12. Although the illustrated configuration employs a plurality of nozzle tips, it is contemplated that a single nozzle tip or a single distributed arrangement of dispenser outlets 48 can be employed. Figure 1 The fluid delivery system 12 can be selectively activated by the user to dispense cleaning fluid to the surface being cleaned. For example, the user can press the actuator 44 to activate the flow control system 36 and dispense cleaning fluid to the surface. The user can then move the cleaning tool 30 across the surface to be cleaned to apply the cleaning fluid to the surface. The user can then release the actuator 44 to deactivate the flow control system 36 and stop the dispensing of cleaning fluid. The user can then move the cleaning tool 30 to a new location on the surface to be cleaned and repeat the process.Figure 1 The illustration can be considered a schematic of an upright deep cleaner (UDC), but selected features in this illustration can be adapted for incorporation into other extractor cleaner configurations, including hand-held and pod-style portable deep cleaners (PDCs).

[0033] An optional fluid heater arrangement 50 can be fluidly interposed between the fluid container 34 and the fluid dispenser 38 to selectively heat the cleaning fluid prior to delivery by the fluid pump 40 through the dispenser outlet 48 to the floor. According to Figure 1 In the illustrated example, an inline electric heater 50 is positioned downstream of the fluid container 34 and upstream of the pump 40. In another example, exhaust from a motor cooling exhaust path of the suction source 18 can be used to heat the cleaning fluid.

[0034] Figure 1 The fluid delivery system 12 of the extractor cleaner 10 can employ a single or multiple reservoirs to store and dispense cleaning fluid or pre-mixed components of a cleaning fluid mixture. For example, a first fluid container 34 can store water, and a second fluid container 52 can store a cleaning agent or additive. By way of example, but not limitation, the two containers 34, 52 can be defined by a supply tank and a collapsible bladder. In one configuration, the fluid container 34 can be a bladder stored within the recovery tank 20. Alternatively, a single fluid container can be fabricated with multiple internal chambers for storing various different liquids. The cleaning fluid in the containers 34, 52 can include, but is not limited to, water or a mixture including water and one or more treatment agents. These treatment agents can include, but are not limited to, a detergent, an odor eliminator, a disinfectant, a stain remover, a deodorizer, a fragrance, or any combination thereof.

[0035] For fluid delivery system architectures employing multiple containers 34, 52, the flow control system 36 can be equipped with a mixing system 54 operable to control the composition of the cleaning fluid delivered to the surface through the dispenser 38. The composition of the cleaning fluid can be determined by a controlled ratio of cleaning fluids mixed together by the mixing system. As Figure 1 As illustrated, the mixing system 54 is represented 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 to an outlet port of the second container 52; when the mixing valve 58 is open, the cleaning fluid component from the second container 52 will flow to the mixing manifold 56. By controlling the valve flow characteristics (timing, frequency, and length) of the mixing valve 58, the composition of the cleaning fluid delivered to the surface can be selected.

[0036] In operation, the extractor cleaner 10 can be prepared for use by electrically connecting the extractor cleaner 10 to the power source 22 and filling one or both of the fluid containers 34, 52 with cleaning fluid or cleaning fluid components. Figure 1The extractable cleaner 10 can selectively deliver metered cleaning fluid to selected surfaces to be cleaned via the fluid delivery system 12 via user activation of the actuator 44. The extractable cleaner 10 can simultaneously move back and forth over the selected surfaces, if desired. The agitator 26 can simultaneously agitate the cleaning fluid onto the selected surfaces. During operation of the fluid recovery system 14, the extractable 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 drawn into the downstream recovery tank 20 where the liquid and debris are substantially separated from the working air. The air stream then passes through the suction source 18 before being exhausted from the extractable cleaner 10. The recovery tank 20 can be periodically emptied of the collected fluid, dirt, and other debris. Additional details of the extractable cleaner, including its component parts, architecture, and uses, have been disclosed in U.S. Patent Nos. 7,784,148, 9,560,948, 10,188,252, 10,588,476, and 10,624,515, the respective entireties of all of which are incorporated by reference herein and for all purposes.

[0037] Turning next to Figures 2 to 5 , a representative example of a multi-roll cleaning head 100 for a vacuum-based extraction cleaner, such as the surface cleaning system 10 of Figure 1 , is shown. 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 concept described below with respect to the cleaning head 100 is similarly applicable to other cleaner heads and other extraction cleaner configurations. The cleaning head 100 is depicted in Figure 2 as having a main (base) housing 102 that is comprised of three parts, generally a suction nozzle housing shell (or front upper shell) 104 that defines a front end of the cleaning head 100, a connector housing shell (or rear upper shell) 106 that is rigidly mounted to the suction nozzle housing shell 104 and defines a rear end of the cleaning head 100, and a lower floor (or lower housing shell) 108 that is positioned below the suction nozzle housing shell 104 and the connector housing shell 106 and is rigidly secured to the suction nozzle housing shell and the connector housing shell. The three shell 104, 106, 108 segments of the main housing 102 collectively define an internal vacuum chamber 101 Figure 3 within the housing 102. An optional pair of (first and second) cover plates 110 and 112 can be secured to the port and starboard (first and second) sides of the main housing 102, respectively. It is contemplated that the main housing 102 can include more or less than three main housing shell segments 104, 106, 108 and two optional cover plates 110, 112 without departing from the intended scope of the present disclosure.

[0038] The ankle docking portion 114 of the connector housing shell 106 is releasably coupled with the leg joint 116 of the upright vacuum cleaner body 122 via a spring-biased locking trigger 118. When the leg joint 116 is received in the ankle docking portion 114 and locked thereto, the connector port 103 of the connector housing shell 106 receives the terminal (bottom) end of the vacuum hose 120 (representing a "fluid conduit") therethrough. The vacuum hose 120 in turn twists into or otherwise physically mates with the rearward open end of the integral hose conduit 105 of the nozzle housing shell 104, thereby fluidly connecting the surface cleaning head 100 to the debris canister and motor / fan assembly (e.g., the suction source 18 and recovery receptacle 20 of the surface cleaning system 10) of the surface cleaning system. The connector port 103, as well as the vacuum hose 120, are fluidly connected to the nozzle inlet 107 of the nozzle housing shell 104 via the hose conduit 105 and the internal vacuum chamber 101. As the cleaning head 100 is moved over a target surface, dirt and debris from the target surface are drawn into the cleaning head 100 through the nozzle inlet 107; the drawn-in dirt / debris passes from the nozzle inlet 107 through the vacuum chamber 101 and the hose conduit 105, and out of the cleaning head 100 through the connector port 103 and hose 120. Figure 1

[0039] For example, to simplify design and ease of manufacture, it can be desirable to have the nozzle housing shell 104, the connector housing shell 106, and the base plate 108 each made as a single-piece monolithic structure (e.g., via injection molding, vacuum forming, multi-shot molding, etc.) of a rigid polymer material. For a one-piece design, the front half of the nozzle housing shell 104 can be structured as an integral roller housing 109 that includes a main roller compartment 111 that adjoins the vacuum chamber 101 and a front guide roller compartment 113 that is located forward of and fluidly coupled with the main roller compartment 111. When the main housing 102 is fully assembled, the roller housing 104 and the base plate 108 can collectively define the nozzle inlet 107, while the nozzle housing's hose conduit 105 and the connector housing shell 106 can collectively define the connector port 103. As an alternative, the forward-most end of the base plate 108 can define an unobstructed roller window 115 (see Figure 2 ), through which larger debris can enter the roller compartment 113 and thus the main housing 102.

[0040] With continuing reference to Figures 2 to 5 , the surface cleaning head 100 is a multi-roller design having a linearly fixed main roller 124 that is located rearward of a linearly adjustable guide roller 126. As Figure 3 and Figure 4 ​Ideally, the main (first) roller 124 is rotatably mounted inside the main roller compartment 111 of the nozzle housing 104, located between the nozzle inlet 107 and the connector port 103 / hose conduit 105. The leading (second) roller 126 is rotatably mounted to the leading roller compartment 113 of the nozzle housing 104, oriented substantially parallel to and in front of the main roller 124. Unlike many conventional multi-roller cleaning head designs, both rollers 124, 126 of the cleaning head 100 are encapsulated within the same integral roller housing 109. As another non-limiting distinction from existing multi-roller cleaning head designs, the fixed main roller 124 can be a surface-agitating brush roller comprising multiple bristle tufts 128, while the floating guide roller 126 can be a padded roller, i.e., without brushes, bristles, bumps, etc., to optimize the suction pressure of the cleaning head. In another example, a roller motor (e.g., Figure 6 The electric motor 230 in the roller motor can be encapsulated within the main housing 102 or otherwise operatively attached to the main housing. The roller motor is drivenly connected to the main roller 124 and is operable to selectively rotate the main roller but not the guide roller 126.

[0041] To facilitate the intake of both large and small debris without compromising the suction pressure of the cleaning head, the guide roller 126 may be a compressible, reduced-diameter (“small and fluffy”) sealed roller located at the front end of the main housing 102. In contrast, the main roller 124 may be a large-diameter cleaning roller with a brush, located behind the guide roller 126, between the vacuum chamber 101 and the nozzle inlet 107. The guide roller 126 may be designed to “float” such that it: (1) automatically rises under the force of large debris upon contact and rolling over it; and (2) automatically falls under gravity after removing large debris, re-engaging with the target surface to maintain continuous suction pressure within the vacuum chamber 101. Figure 4 In the example shown, the main roller 124 has a first (roller) diameter D. R1 Its diameter D is greater than that of the second (roller) of guide roller 126. R2 When the brush bristle tuft 128 includes the main roller, for example, the diameter D of the main roller... R1 The diameter D of the guide roller R2 Two to three times larger. The smaller diameter D of the floating guide roller 126. R2 The guide roller 126 is allowed to have relatively large vertical displacement without significantly increasing the encapsulation space within the main cleaning head housing 102. It is conceivable that some applications could use guide rollers with a diameter larger than that of the main roller.

[0042] refer to Figure 5A representative guide roller 126 is depicted as a roller with a soft "shield," characterized by the absence of bristles, bumps, flexible flaps, etc., such that the outermost periphery of roller 126 is flush with and thus seals to the target surface. Guide roller 126 may include an elongated, hollow roller shaft 128 having a tubular, compressible roller sleeve 130 pressed against and covering the roller shaft 128. A pair (first and second) friction wheels 132 and 134 are rigidly fixed to the opposite (first and second) longitudinal ends of roller shaft 128, for example, via splines or keyways. The outer periphery of each friction wheel 132, 134 may be covered with surface-engaging teeth, treads, pads, or other features that increase friction. A pair (first and second) cylindrical mounting pins 136 and 138 (also referred to herein as "bearings") are each integrally formed with and project axially from the outer surface of a corresponding one of the friction wheels 132, 134. To rotate the guide roller 126, the friction wheels 132 and 134 are driven by the frictional force generated by the target surface when the user pushes or pulls the surface cleaning head 100 past the target surface (i.e., without an electric motor input driving torque). The mounting pins 136 and 138 can be configured as flat bearings or roller bearings to facilitate smooth rotation of the guide roller 126.

[0043] Passive linear adjustment of the vertical height of the floating roller can be achieved through the sliding engagement of the guide roller 126 with the main housing 102. By way of a non-limiting example, Figure 5 A pair of (first and second) linear pin slots 117 and 119 are shown, each extending through corresponding mounting walls 121 and 123 within the guide roller compartment 113 of the nozzle housing 104 of the cleaning head. Mounting pins 136, 138 of each guide roller are slidably mounted within the corresponding linear pin slots 117 and 119, allowing the guide roller 126 to float freely within the main housing 102 (e.g., in a reciprocating linear motion manner). By using this free-floating arrangement, instead of the spring-biased, pivotally mounted roller support housing used in other multi-roller cleaning head designs, the guide roller 126 is in a lowered position within the linear pin slots 117, 119 (…). Figure 3 ) and rising position ( Figure 4 Slide freely between (e.g., in) Figure 5 (Moves up and down). Therefore, the guide roller 126 is biased from the raised position to the lowered position under the action of gravity, that is, there is no need to use a return spring or other biasing mechanism.

[0044] Next, turn to Figure 6 and 7 This illustrates a non-limiting example of a roller drive system 200 for transmitting drive torque to floating auxiliary rollers in a multi-roller cleaning head. Although the appearance differs, it is conceivable that the above-mentioned... Figures 2 to 5 Any features and options described in the Multi-Roller Cleaning Head 100 can be incorporated individually or collectively.Figure 6 and 7 In the multi-roller drive system 200 configuration of

[0045] The torque-transferring roller drive system 200 is depicted in Figure 6 and Figure 7 as a belt-driven drive system having a central axle 202 that is rotatably attached to a cleaner head housing (e.g., the main housing 102 of Figure 2 ) such that the axle 202 is substantially parallel to and between the main roller 224 and the guide roller 226. The central axle 202 carries a pair of (first and second) axle wheels 204 and 206 (e.g., the term "wheel" can refer to a gear wheel, a pulley, a sprocket, etc.) and rotates in unison therewith. The main (first) axle wheel 204 is drivingly connected to a main (first) roller wheel 210 of the main roller 224 via a main (first) continuous belt 208. Likewise, the guide (second) axle wheel 206 is drivingly connected to a guide (second) roller wheel 214 of the guide roller 226 via a guide (second) belt 212.

[0046] According to the example shown in Figure 6 , the main axle wheel 204 has a main (first) axle wheel diameter D AW1 , and the guide axle wheel 206 has a guide (second) axle wheel diameter D AW2 that is less than the first axle wheel diameter D AW1 . Further, the main roller wheel 210 has a main (first) roller wheel diameter D RW1 that is less than the wheel diameter D AW1 of the main axle wheel 204 and greater than the wheel diameter D AW2 of the guide axle wheel 206. In comparison, the guide roller wheel 214 has a guide (second) roller wheel diameter D RW2 that is greater than the guide axle wheel diameter D AW2 but less than the main axle wheel diameter D AW1The motor torque output by the motorized roller 230 can be transmitted to the primary roller 224, from the primary roller 224 to the central axle 202 via the primary roller wheel 210, the belt 208, and the axle wheel 204. The central axle 202 then transmits this motor torque to the guide roller 226 via the guide axle wheel 206 and the belt 212, through the guide roller wheel 214. It is contemplated that the diameters of the various wheels of the torque transmission wheels and the relative wheel diameters can be different than those shown. Figure 6

[0047] To enable the central axle 202 and the guide roller 226 to be rotatably and slidably mounted to the main housing of the cleaning head, a mounting wall or plate 216 Figure 7 ) is attached to or integrally formed with the main housing and operatively supports the axle 202 and the roller 226. The mounting wall / plate 216 includes a pair (first and second) axle slots 215 and 217; the central (first) axle slot 215 can be arcuate (e.g., the radial center point of the slot 215 arc is the rotational axis of the primary roller 210), and the guide (second) axle slot 217 can be linear. The central axle 202 is slidably mounted inside the central axle slot 215 to translate along an arcuate path D P1 , while the guide roller 226 is slidably mounted inside the guide axle slot 217 to translate along a linear path D P2 . The central slot 215 can be vertically and horizontally offset from the guide slot 217, such that the central axle 202 is vertically and horizontally offset from the guide roller 226. The second linear path D P2 of the guide roller 226 can be at an oblique angle (e.g., about 20 P1 to 30 o degrees) relative to the first linear path D o of the central axle 202. The primary roller 224 can be pivotably attached to the central axle 202 via a primary (first) pair of control arms or brackets 218, while the guide roller 226 can be pivotably attached to the central axle 202 via a guide (second) pair of control arms or brackets 220. The primary control arms / brackets 218 can be at an angle relative to the guide control arms / brackets pair 220, e.g., at an offset angle a of about 100 o to 130 o degrees. With this arrangement, a large debris can pass under one end of the guide roller 226 and only lift said one end of the guide roller 226; at the same time, the other end of the guide roller 226 can remain in a first (lowered) position without causing the guide roller 226 to malfunction.

[0048] Additional features can be reflected in the following clauses:

[0049] ​Clause 1 : A surface cleaning head for a surface cleaning system that includes a fluid conduit and a suction device fluidly connected to the fluid conduit and operable to generate a suction force, the surface cleaning head comprising: a main housing having a first linear pin slot and a second linear pin slot, a suction nozzle inlet configured to suction debris from a target surface, and a connector port fluidly connected to the suction nozzle inlet and configured to couple with the fluid conduit, thereby fluidly connecting to the suction device; a first roller rotatably attached to the main housing and interposed between the suction nozzle inlet and the connector port; a roller motor attached to the main housing, drivingly connected to the first roller, and operable to selectively rotate the first roller; and a second roller rotatably attached to the main housing substantially parallel to the first roller, the second roller comprising a roller shaft having a first mounting pin and a second mounting pin protruding from opposite first and second ends 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.

[0050] Clause 2: The surface cleaning head of clause 1, wherein the second roller freely slides within the first and second linear pin slots between a lowered position and a raised position located above the lowered position.

[0051] Clause 3: The surface cleaning head of clause 2, wherein the second roller is biased from the raised position to the lowered position by gravity without a spring force of a spring.

[0052] Clause 4: The surface cleaning head of any of clauses 1-3, wherein the main housing comprises a suction nozzle housing shell at least partially defining the suction nozzle inlet and a connector housing shell mounted to the suction nozzle housing shell and at least partially defining the connector port, wherein both the first and second rollers are rotatably mounted inside the suction nozzle housing shell.

[0053] Clause 5: The surface cleaning head of clause 4, wherein the suction nozzle housing shell is a single piece structure comprising a roller housing that defines a main roller compartment in which the first roller is mounted and a front guide roller compartment in which the second roller is mounted.

[0054] Clause 6: The surface cleaning head of clause 5, wherein the suction nozzle housing shell further comprises a single piece bottom plate rigidly attached to the connector housing shell and the roller housing, the bottom plate and the roller housing collectively defining the suction nozzle inlet.

[0055] Clause 7: The surface cleaning head of any of clauses 1-6, wherein the first roller has a first roller diameter, and the second roller has a second roller diameter that is less than the first roller diameter.

[0056] Clause 8: The surface cleaning head of any of clauses 1-7, wherein the first roller is a brush roller comprising a plurality of bristles, and the second roller is a pad-equipped roller that is free of bristles.

[0057] Clause 9: The surface cleaning head of any of clauses 1-8, wherein the second roller is frictionally driven by a frictional force generated by the target surface without a torque force of a motor.

[0058] Clause 10: The surface cleaning head of clause 9, wherein the second roller comprises a first friction wheel and a second friction wheel rigidly fixed to the first end and the second end of the roller shaft, respectively, and wherein the first mounting pin and the second mounting pin are integrally formed with the first friction wheel and the second friction wheel, respectively.

[0059] Clause 11 : The surface cleaning head of any of clauses 1-10, further comprising a belt drive system having a central axle shaft attached to the main housing parallel to and between the first roller and the second roller, the central axle shaft supporting a first axle wheel and a second axle wheel, the first axle wheel drivingly connected to a first roller wheel of the first roller via a first belt, and the second axle wheel drivingly connected to a second roller wheel of the second roller via a second belt.

[0060] Clause 12: The surface cleaning head of clause 11, wherein the first axle wheel has a first axle diameter, the second axle wheel has a second axle diameter that is less than the first axle diameter, the first roller wheel has a first roller diameter that is less than the first axle diameter, and the second roller wheel has a second roller diameter that is less than the second axle diameter.

[0061] Clause 13: The surface cleaning head of clause 11, wherein the main housing further comprises a pair of linear axle slots, the central axle shaft is slidably mounted within the pair of linear axle slots to translate along a first linear path, and wherein the second roller translates along a second linear path that is inclined relative to the first linear path.

[0062] Clause 14: A surface cleaning system comprising: a cleaner body; a recovery bin attached to the cleaner body and configured to house therein debris extracted from a target surface; a suction device attached to the cleaner body, fluidly coupled to the recovery bin and configured to generate suction to draw the debris into the recovery bin; a hose fluidly connected to the recovery bin and the suction device; and a surface cleaning head attached to the cleaner body and comprising: a main housing having a first linear pin slot and a second linear pin slot, a suction inlet configured to draw the debris from the target surface, and a connector port fluidly connected to the suction inlet and coupled to the hose, thereby fluidly connecting the surface cleaning head to the recovery bin and the suction device; a main roller rotatably attached to the main housing and interposed between the suction inlet and the connector port; a roller motor attached to the main housing, drivingly connected to the main roller and operable to selectively rotate the main roller; and an auxiliary roller rotatably attached to the main housing substantially in parallel to and forward of the main roller, the auxiliary roller comprising a roller shaft having a first mounting pin and a second mounting pin protruding from opposite first and second ends of the roller shaft and slidably mounted in the first and second linear pin slots, respectively, such that the auxiliary roller floats in the main housing, wherein the auxiliary roller unimpededly slides along a straight path between a lowered position and a raised position located above the lowered position, the auxiliary roller is biased from the raised position to the lowered position by gravity without a spring force of a spring.

[0063] Clause 15: A method of assembling a surface cleaning head for a surface cleaning system, the surface cleaning system including a fluid conduit and a suction device fluidly connected to the fluid conduit and operable to generate a suction force, the method comprising: receiving a main housing of the surface cleaning head, the main housing having first and second linear pin slots, a suction nozzle inlet configured to suction debris from a target surface, and a connector port fluidly connected to the suction nozzle inlet; coupling the connector port with the fluid conduit, thereby fluidly connecting 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 suction 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 having first and second mounting pins protruding from opposite first and second ends 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.

[0064] Clause 16: The method of clause 15, wherein the second roller freely slides within the first and second linear pin slots between a lowered position and a raised position located above the lowered position, the second roller being biased from the raised position to the lowered position by gravity without a spring force of a spring.

[0065] Clause 17: The method of clauses 15-16, wherein the main housing includes a suction nozzle housing shell at least partially defining the suction nozzle inlet and a connector housing shell mounted to the suction nozzle housing shell and at least partially defining the connector port, wherein both the first and second rollers are rotatably mounted inside the suction nozzle housing shell.

[0066] Clause 18: The method of clause 17, wherein the suction nozzle housing shell is a single-piece structure including a roller housing that defines a main roller compartment in which the first roller is mounted and a front guide roller compartment in which the second roller is mounted.

[0067] Clause 19: The method of clause 18, wherein the suction nozzle housing shell further includes a single-piece bottom plate rigidly attached to the connector housing shell and the roller housing, the bottom plate and the roller housing collectively defining the suction nozzle inlet.

[0068] Clause 20: The method of any one of clauses 15-19, wherein the first roller has a first diameter and the second roller has a second diameter that is less than the first diameter.

[0069] Clause 21 : The method of any one of clauses 15-20, wherein the first roller is a brush roller comprising a plurality of bristles, and the second roller is a pad-equipped roller without bristles.

[0070] Clause 22: The method of any one of clauses 15-21, wherein the second roller comprises a first friction wheel and a second friction wheel rigidly fixed to the first end and the second end of the roller shaft, respectively, wherein the first mounting pin and the second mounting pin are integrally formed with the first friction wheel and the second friction wheel, respectively, and wherein the second roller is frictionally driven by a frictional force generated by the target surface without a torque force of a motor.

[0071] Clause 23: The method of any one of clauses 15-22, further comprising: attaching a belt drive system to the main housing, the belt drive system comprising a central axle shaft parallel to and interposed between the first roller and the second roller, the central axle shaft supporting a first axle wheel and a second axle wheel; drivingly connecting the first axle wheel to a first roller wheel of the first roller via a first belt; and drivingly connecting the second axle wheel to a second roller wheel of the second roller via a second belt.

[0072] Clause 24: The method of clause 23, wherein the first axle wheel has a first axle diameter, the second axle wheel has a second axle diameter that is less than the first axle diameter, the first roller wheel has a first roller diameter that is less than the first axle diameter, and the second roller wheel has a second roller diameter that is less than the second axle diameter.

[0073] Clause 25: The method of clause 24, wherein the main housing further comprises a pair of linear axle slots within which the central axle shaft is slidably mounted to translate along a first linear path, and wherein the second roller translates along a second linear path that is inclined relative to the first linear path.

[0074] While some representative modes have been described in detail herein, various alternative designs and embodiments exist for practicing the present teachings defined in the following claims. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It is therefore intended that the scope of the teachings embraced by the claims should not be limited by the particular representative modes described above. Moreover, the present concept expressly embraces combinations and sub-combinations of the elements and features disclosed herein. The detailed description and drawings are supportive and descriptive of the present teachings, but the scope of the present teachings should be defined by the claims and their equivalents.

Claims

1. A surface cleaning head for a surface cleaning system comprising a fluid conduit and a suction device fluidly connected to the fluid conduit and operable to generate a suction force, the surface cleaning head comprising: a main housing having a first linear pin slot and a second linear pin slot, a suction nozzle inlet configured to draw in debris from a target surface, and a connector port fluidly connected to the suction nozzle inlet and configured to couple with the fluid conduit, thereby fluidly connecting to the suction device; a first roller rotatably attached to the main housing and interposed between the suction nozzle inlet and the connector port; a roller motor attached to the main housing, drivingly connected to the first roller, and operable to selectively rotate the first roller; and a second roller rotatably attached to the main housing substantially parallel to the first roller, the second roller comprising a roller shaft having a first mounting pin and a second mounting pin protruding from opposite first and second ends 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.

2. The surface cleaning head of claim 1, wherein the second roller freely slides within the first and second linear pin slots between a lowered position and a raised position located above the lowered position.

3. The surface cleaning head of claim 2, wherein the second roller is biased from the raised position to the lowered position by gravity without a spring force of a spring.

4. The surface cleaning head of claim 1, wherein the main housing comprises a suction nozzle housing shell at least partially defining the suction nozzle inlet and a connector housing shell mounted to the suction nozzle housing shell and at least partially defining the connector port, wherein the first and second rollers are both rotatably mounted inside the suction nozzle housing shell.

5. The surface cleaning head of claim 4, wherein the suction nozzle housing shell is a single-piece structure comprising a roller housing defining a main roller compartment in which the first roller is mounted and a front guide roller compartment in which the second roller is mounted.

6. The surface cleaning head of claim 5, wherein the suction nozzle housing shell further comprises a single-piece bottom plate rigidly attached to the connector housing shell and the roller housing, the bottom plate and the roller housing collectively defining the suction nozzle inlet.

7. The surface cleaning head of claim 1, wherein the first roller has a first roller diameter and the second roller has a second roller diameter that is less than the first roller diameter.

8. The surface cleaning head of claim 1, wherein the first roller is a brush roller comprising a plurality of bristles and the second roller is a pad-equipped roller that is free of bristles.

9. The surface cleaning head of claim 1, wherein the second roller is frictionally driven by a frictional force generated by the target surface without a torque force of a motor. ​ 10. The surface cleaning head of claim 9, wherein the second roller includes first and second friction wheels rigidly fixed to the first and second ends of the roller shaft, respectively, and wherein the first and second mounting pins are integrally formed with the first and second friction wheels, respectively.

11. The surface cleaning head of claim 1, further comprising a belt drive system having a central axle shaft attached to the main housing parallel to and between the first and second rollers, the central axle shaft supporting first and second axle wheels, the first axle wheel drivingly connected to first roller wheels of the first roller via a first belt, and the second axle wheel drivingly connected to second roller wheels of the second roller via a second belt.

12. The surface cleaning head of claim 11, wherein the first axle wheel has a first axle diameter, the second axle wheel has a second axle diameter less than the first axle diameter, the first roller wheels have a first roller diameter less than the first axle diameter, and the second roller wheels have a second roller diameter less than the second axle diameter.

13. The surface cleaning head of claim 11, wherein the main housing further comprises a pair of linear axle slots within which the central axle shaft is slidably mounted to translate along a first linear path, and wherein the second roller translates along a second linear path that is inclined relative to the first linear path.

14. A surface cleaning system comprising: a cleaner body; a recovery container attached to the cleaner body and configured to house therein debris extracted from a target surface; a suction device attached to the cleaner body, fluidly coupled to the recovery container, and configured to generate suction to draw the debris into the recovery container; a hose fluidly connected to the recovery container and the suction device; and a surface cleaning head attached to the cleaner body and comprising: a main housing having first and second linear pin slots, a suction inlet configured to draw the debris from the target surface, and a connector port fluidly connected to the suction inlet and coupled to the hose, thereby fluidly connecting the surface cleaning head to the recovery container and the suction device; a primary roller rotatably attached to the main housing and interposed between the suction inlet and the connector port; a roller motor attached to the main housing, drivingly connected to the primary roller, and operable to selectively rotate the primary roller; and a secondary roller rotatably attached to the main housing substantially parallel to and forward of the primary roller, the secondary roller comprising a roller shaft having first and second mounting pins protruding from opposite first and second ends of the roller shaft and slidably mounted in the first and second linear pin slots, respectively, such that the secondary roller floats in the main housing. ​ wherein the secondary roller is unimpededly slidable along a straight path between a lowered position and a raised position located above the lowered position, the secondary roller being biased from the raised position to the lowered position by gravity without a spring force of a spring.

15. A method of assembling a surface cleaning head for a surface cleaning system, the surface cleaning system including a fluid conduit and a suction device fluidly connected to the fluid conduit and operable to generate a suction force, the method comprising: receiving a main housing of the surface cleaning head, the main housing having first and second linear pin slots, a suction inlet configured to suction debris from a target surface, and a connector port fluidly connected to the suction inlet; coupling the connector port with the fluid conduit, thereby fluidly connecting 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 suction 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 having first and second mounting pins protruding from opposite first and second ends of the roller shaft and slidably mounted in the first and second linear pin slots, respectively, such that the second roller is floating in the main housing.

16. The method of claim 15, wherein the second roller is unimpededly slidable within the first and second linear pin slots between a lowered position and a raised position located above the lowered position, the second roller being biased from the raised position to the lowered position by gravity without a spring force of a spring.

17. The method of claim 15, wherein the main housing includes a suction housing shell at least partially defining the suction inlet and a connector housing shell mounted to the suction housing shell and at least partially defining the connector port, wherein both the first and second rollers are rotatably mounted inside the suction housing shell.

18. The method of claim 17, wherein the suction housing shell is a single piece structure including a roller housing defining a main roller compartment in which the first roller is mounted and a front roller compartment in which the second roller is mounted.

19. The method of claim 18, wherein the suction housing shell further includes a single piece bottom plate rigidly attached to the connector housing and the roller housing, the bottom plate and the roller housing collectively defining the suction inlet.

20. The method of claim 15, wherein the first roller has a first diameter and the second roller has a second diameter that is less than the first diameter.

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