Patent Application
20110107540
The present invention generally relates to surface cleaning equipment. More particularly the present invention relates to a squeegee assembly having a novel attachment and non-destructive release mechanism for use with such equipment.
Surface maintenance vehicles and cleaning devices have a long history subject to gradual innovation and improvement toward improved and oftentimes automated performance in removing debris and contamination from floors. These vehicles and devices may be self-powered, towed, or pushed, and/or manually powered and may carry a human operator during cleaning operations. Such vehicles and devices include scrubbers, extractors, sweepers and vacuums, as well as combinations thereof, intended for cleaning, scrubbing, wiping and/or drying a portion of a substantially flat surface both indoors and outdoors. Many such vehicles and devices employ a squeegee assembly for removing solution from a floor which has been cleaned by application of a cleaning solution of water and a detergent in conjunction with scrubbing action of one or more moving brushes. Accordingly, the squeegee assembly of such prior art cleaning vehicles often mounts at or near the rear of the surface maintenance vehicle to direct the solution to a removal location where the solution (including suspended dirt, particles and contaminants) is removed. The cleaning solution is typically supplied to the floor surface through or near rotary scrub brushes operating from a lower portion of the vehicle. The squeegee assembly may include a squeegee supporting member of generally arcuate configuration with two squeegee blades spaced apart and affixed to the supporting member to promote consistent contact with the surface to be cleaned and wiped.
In some prior art cleaning vehicles having two squeegee blades, a vacuum source may couple to the wiping assembly to lift the loaded cleaning solution from the space between the blades to a remote reservoir or other collection unit. The squeegee assembly is often sufficiently wide to at least fully cover the path width of the scrub brushes and/or the wheels of the cleaning vehicle. Consequently, at least the ends of the squeegee assembly tend to be exposed at the sides of the vehicle and are therefore potentially very vulnerable to contact with stationary objects which might be encountered during operation of the vehicle during cleaning operations and when transporting the vehicle between cleaning operations. Solid contact between an end of a squeegee assembly and a stationary object such as, for example, a vertical support column, can result in substantial and costly damage to not only the squeegee assembly but also the surface maintenance vehicle itself resulting in downtime, costly repair and/or replacement of all or a part of the vehicle (as well as the stationary object) and in some circumstances causing damage or injury to the human operator of the vehicle as well.
U.S. Pat. No. 6,602,018, to Feeny et al., entitled “Squeegee Assembly Having a Non-Destructive Release Mode”, is incorporated by reference herein. Prior art squeegee assembly couplings use a compliant bushing that has a portion of the bushing captured by the squeegee assembly and the remainder of the bushing captured in the squeegee suspension. A threaded fastener is used to secure the bushing between the squeegee assembly and the squeegee suspension. The pocket profile in the squeegee suspension allows for the through hardware to be released through an open ended slot profile and also incorporates a pocket for the portion of the compliant bushing. The through hardware will hold the assembly together for normal operation. When the squeegee assembly strikes a rigid/semi-rigid object the bushing exits the open slot so as to free the squeegee assembly from the squeegee suspension.
The threaded hardware of the prior art is difficult and time-consuming to work with, and is a burden to work with as it is located in a dirty environment and the threads become contaminated. Thus, there is a need for an improved releasable coupling for a squeegee assembly which has improved features.
The present invention teaches, enables and discloses an improved mechanical coupling for a squeegee assembly usable in a surface maintenance vehicle. Such a vehicle includes those self-powered and manually powered cleaning vehicles applied to the task of removing loaded cleaning solution from a cleaned surface and preferably include all such vehicles using a squeegee assembly; although rigid or fixed wiper assemblies for such vehicles benefit from the teaching of this disclosure. Such a surface may comprise an interior or exterior floor having some limited porosity but preferably comprising finished concrete (whether painted or sealed), asphalt, ceramic tile, resin-based tile, and the like and including most types of flooring typical of commercial and industrial-grade facilities. However, the teaching hereof finds application in diverse handling of fluids, whether or not “loaded,” naturally-occurring liquid(s) or pure cleaning fluid.
Accordingly, the releasable coupling for a squeegee assembly of the present invention tolerates a wide variety of stresses imparted to the blade portions of a squeegee assembly during wiping operations and before becoming disconnected from a surface maintenance vehicle to which it is coupled. In most embodiments of the present invention, the squeegee assembly is coupled to a suspension mount coupled to the maintenance vehicle and typically designed to permit the squeegee assembly to articulate, or “float,” thereby maintaining contact between one or more wiper blades secured to the squeegee assembly and a portion of the surface to be cleaned during operation of the surface maintenance vehicle. A squeegee assembly utilizing the teaching of the present invention thus may be raised, lowered, pivoted and/or rotated either passively using gravity or manually using gearing, cables and the like and/or via internal combustion, electric, pneumatic, hydraulic or other motive means.
While not required to practice the present invention, in one preferred embodiment of the present invention at least two squeegee blades are both secured to a vacuum core which forms a substantially sealed chamber when biased toward the surface to be cleaned. A source of vacuum is applied to a port formed in a side of the sealed chamber to evacuate the loaded liquid and the like from the sealed chamber to a storage vessel or reservoir in anticipation of later disposal.
During cleaning operations, as the maintenance vehicle is propelled forward over a portion of a surface to be cleaned, when the squeegee assembly contacts a relatively stationary object, or otherwise becomes subject to instantaneous or very rapidly increasing resistance to forward movement, the improved mechanical coupling for the squeegee assembly initially absorbs some of the stresses imparted to the squeegee assembly. Typically, portions of each improved mechanical coupling designed to absorb the stress forces will deform most nearest the location of increasing resistance to forward movement, and may either become fully disconnected if the stress force reaches a threshold force value or recoil to the original mounting location after absorbing forces that are less than said threshold force value. The threshold value force at which a squeegee assembly dislodges from its mounting location is designed to avoid damage to the squeegee assembly, the mounting member (if any), and the maintenance vehicle itself. The threshold force value may vary but due to the design of the improved mechanical coupling of the present invention, said threshold force value should have a substantially similar magnitude independent of the axial compressive force applied each time the mechanical coupling attaches a squeegee assembly to a maintenance vehicle.
In a preferred form, the improved mechanical coupling comprises a resilient compliant bushing, capable of absorbing stress primarily in a horizontal plane opposing to a forward direction of travel for the maintenance vehicle. The compliant bushing is preferably cylinder-shaped having a substantially common-radius central aperture, or passageway, and an enlarged head feature having an increased outer radius on one end thereof.
In addition, in combination with the compliant bushing (and biasing feature for ease of mounting and remounting same) a substantially non-deformable central sleeve member resides within a common-radius central aperture thereof to limit the deformation of the compliant bushing, thereby functioning as a mechanical “travel stop” feature, and thus creating a fairly uniform and limited range of compressive force for the entire assembly when operatively coupled to a maintenance vehicle. Of course, a variety of different components may be substituted for the central sleeve member as a travel stop. Thus, the compliant bushing may include a relatively rigid stop element, such as a sleeve member formed of material designed to withstand deformation in an axial direction, through which an actuation rod is received during assembly. The sleeve may be metal and operatively limit the degree of deformation of the compliant bushing during assembly and reinstallation subsequent to detachment of the squeegee assembly during operation.
In a most preferred embodiment, mechanical biasing of the deformable member is provided by a biasing structure inserted into the interior of the central sleeve member designed to support the deformable member in a desired pre-mount configuration. The mechanical biasing includes an actuation rod attached to an over-center lever and to a resilient spring and retainer at an opposite end.
The suspension mount preferably comprises a set of two open-ended discrete collar-shaped, or generally semi-circular, mounts having an open channel formed opposite the direction of travel of the maintenance vehicle. The open-ended mounts may be ovoid, toroidal, annular, or even rectangular-shaped mounts, and the like as long as the open channel, or spacing, is provided therein so that the compliant bushing may exit thereof when a threshold value force impacts the squeegee assembly.
Similarly the squeegee assembly frame preferably comprises a set of two open-ended discrete collar-shaped, or generally semi-circular, mounts having an open channel formed opposite the direction of travel of the maintenance vehicle. The open-ended mounts may be ovoid, toroidal, annular, or even rectangular-shaped mounts, and the like as long as the open channel, or spacing, is provided therein so that the compliant bushing may exit thereof when a threshold value force impacts the squeegee assembly
In general, the improved mechanical coupling of the present invention comprises subcomponents shaped to cooperate with other subcomponents and not limited to type of motive force applied although all elements of the improved mechanical coupling are preferably tightened, and loosened, manually.
One object of the invention is to provide a squeegee assembly for a surface maintenance vehicle which is tolerant of stress forces imparted to the squeegee assembly and designed to progressively begin to separate from the vehicle as cumulative stresses upon the squeegee assembly from a physical obstacle, such as a stationary object, grow toward a threshold force value.
Another object of the present invention is to provide a squeegee assembly for a surface maintenance vehicle which is releasably connected to the vehicle via one or more compliant bushings having a pre-selected release mode intended to preserve in good working order the components of the squeegee assembly, the surface maintenance vehicle, and the physical obstacle encountered by the squeegee assembly as well as the operator of the vehicle.
Another object of the present invention is to teach, enable and disclose a class of mechanical coupling assemblies useable for connecting a squeegee assembly to a surface maintenance vehicle having a predetermined release force threshold which is generally the same for each of a plurality of such coupling assemblies and is substantially independent of the degree of compressive stress imparted to the mechanical coupling when first connected.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
Industrial sweeper-scrubbers which may use the present invention are shown in
The present invention is concerned with releasably securing the squeegee assembly 20 to these types of vehicles, and not the sweeping or other functional aspects of the vehicles. The particular surface maintenance vehicles illustrated in
Referring to
Squeegee assembly 20 includes front and rear flexible blades 22, 24 mounted to a vacuum core structure 26 so that blades 22, 24 are spaced at the center and taper towards each other so that the ends are closely adjacent and/or tight against each other in the preferred form shown. The front blade 22 has notches or slots in the free edge along its length to allow solution to pass therethrough. Blades 22 and 24 contact the floor surface. Blades 22 and 24 are made from suitable material such as gum rubber, neoprene, urethane, or the like. A suction tube 30 is provided in vacuum core structure 26 in fluid communication between blades 22 and 24 adjacent the centers thereof and to which a vacuum can be supplied such that air and solution are pulled in through the slots in the front blade 22 or pulled from underneath the front blade 22 and flow out of tube 30, with the rear blade 24 acting as a wiper to leave the floor surface dry. Suction tube 30 is in fluid communication with a recovery tank in turn in fluid communication with a vacuum assembly which draws air from the hollow interior of the recovery tank. An example of a squeegee assembly is disclosed in U.S. Provisional Patent Application No. 61/259,421, filed Nov. 9, 2009, which is incorporated herein by reference in its entirety.
In the preferred form shown, blade 24 has a thickness less than blade 22 but could have equal thickness or different relative thicknesses according to the particular material from which blades 22 and 24 are formed. Likewise, in an unflexed and vertical position, blade 24 has a lower extent elevated above the lower extent of blade 22 in the form shown. In a preferred form, blades 22 and 24 are reversible so that both elongated edges can be oriented to be the lower wiping edges.
Front blade 22, rear blade 24 and vacuum core 26 are held against frame 50 via clamp band 52. Frame 50 includes clamp band engaging hooks 56 near ends of frame 50. Clamp band 52 includes a stationary latch 58 on one end and a movable latch 60 on the other end. Movable latch 60 is selectively manipulated to secure clamp band 52 to frame 50.
In one preferred form, squeegee assembly 20 is releasably coupled to squeegee mount 21. Squeegee mount 21 is connected to a pivot mount 62 which is adapted to pivot about an axis 64. The angular orientation of squeegee mount 21 relative to pivot mount 62 can be adjusted by changing the length of adjustment rod 65 and/or changing the height of adjustable caster wheels 68 using knobs 70. The angular orientation of pivot mount 62 relative to the machine 10 can be adjusted via electric actuator 66 using known control devices. Caster wheels 68 support the squeegee assembly 20 as the machine traverses a floor surface. One of the caster wheels 68 and knobs 70 are removed from
Squeegee assembly 20 is releasably connected to squeegee mount 21. That is, upon contact with a substantial object, the squeegee assembly 20 is designed to break away from the squeegee mount 21. As described herein, a pair of compliant bushings 72 are used to releasably couple the frame 50 of squeegee assembly 20 to the squeegee mount 21. The compliant bushings 72 are held between the squeegee frame 50 and squeegee mount 21 at the coupling receiving areas by over-center levers 74, which preferably may be tightened or loosened by hand. Over center levers 74 are designed on the principle of variable mechanical advantage, and therefore, variable hand effort. During the initial movement of the lever from the “off” to the “on” position, there is great linear movement compared to the output effort. As the lever approaches the “on” position, the output effort becomes greater in comparison to the linear movement. As the lever passes over center, or toggle position, the mechanical advantage is greatest. Levers 74 with over-center toggle action keep the squeegee assembly secured to the surface maintenance machine, and prevent accidental opening due to shock or vibration. Levers 74 include long handles for comfortable grip.
Referring to
Referring to
Preferably, the releasable coupling assembly includes a pair of compliant bushings 72. However, it will be appreciated that other numbers of matching components may be utilized.
Referring to
In the position shown in
As described herein, the compliant bushings 72 are deformable (along a substantially horizontal plane) during an obstruction contact condition in which the squeegee assembly 20 is released from the surface maintenance vehicle. During a release operation, the compliant bushings 72 are temporarily deformed as they pass along and through the channel portions 84, 94 of the coupling receiving areas 80, 90 prior to separation of the squeegee assembly 20 from the surface maintenance vehicle. During the release operation, the compliant bushings 72 provide both a resistive “shearing”-type force as the head portions 100 of the compliant bushings 72 pass through the channel portions 84, 94 of the coupling receiving areas 80, 90, and a frictional force developed between the upper, lower and side surfaces of the compliant bushings 72 in contact with surfaces of the coupling receiving areas.
Subsequent to a release operation, a squeegee assembly 20 may be reconnected to a surface maintenance vehicle by releasing the levers 74 a sufficient amount to allow compliant bushings 72 to be received into their respective coupling receiving areas 80, 90 and then tightening the levers 74 to an extent limited by sleeves 104.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
This application claims the benefit of U.S. Provisional Application No. 61/259,428, filed Nov. 9, 2009, and incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61259428 | Nov 2009 | US |
