Squeegee assembly having a non-destructive release mode

#The present invention relates to surface cleaning equipment. More particularly the present invention relates to a novel mechanical coupling for retaining a wiper assembly to a surface maintenance vehicle that preserves the wiper assembly from damage in event of contact with oversize debris, a stationary object or other impediments and obstacles which create significant resistance to the desired motion of the wiper assembly.

#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 wiping dry 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. In this disclosure, the term “loaded cleaning solution” shall apply to such a cleaning solution after application thereof to a floor or other surface to be cleaned. 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.

#Preferred embodiments of the invention will be described in detail hereinafter with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout.

#FIG. 1. is an elevational side view of an exemplary self-propelled surface maintenance vehicle employing an embodiment of the articulated wiper assembly having a vacuum source fluidly coupled thereto and wherein a human user controls and operates the vehicle from an integrated operator station disposed on and near the rear of the vehicle so that when the vehicle is propelled forward during cleaning the articulated wiper assembly completes a final step comprising wiping the surface and evacuating loaded cleaning solution via the vacuum source.

#FIG. 2 is an elevational side view of an exemplary surface maintenance vehicle employing an embodiment of the articulated wiper assembly and wherein a human user controls and operates the vehicle while walking behind the vehicle.

#Industrial sweeper-scrubbers which may use the present invention are shown in FIGS. 1 and 2. These surface maintenance machines may be used for sweeping and/or scrubbing floors in factories, warehouses, and other industrial or commercial establishments. As shown in FIG. 1, a riding-type surface maintenance vehicle 20 has a frame 22, and is supported on a plurality of front and rear wheels. Typically, such a surface maintenance vehicle 20 includes a variety of implements such as brushes and systems for dispensing cleaning solutions typically composed of detergent and water which suspend dirt. Herein, a cleaning solution containing suspended dirt and other particles shall be called a “loaded cleaning solution.” Loaded cleaning solution and other liquid material are usually removed by a wiper blade assembly, referred to herein from time to time as an articulated wiper assembly. Such an articulated wiper assembly 90 is often mechanically coupled near the rear of a surface maintenance vehicle 20. Such an articulated wiper assembly 90 is operatively connected to the surface maintenance vehicle 20 by a releasable attachment device 38 as further described in more detail herein. One example of such a surface maintenance vehicle is disclosed in U.S. Pat. No. 5,455,985, assigned to Tennant Company, the assignee herein, and incorporated herein by reference in its entirety.

#Alternatively, FIG. 2 illustrates a walk-behind surface maintenance vehicle, such a floor scrubbing vehicle disclosed in U.S. Pat. No. 5,483,718, assigned to Tennant Company, the assignee herein, and incorporated herein by reference in its entirety. As with the above-mentioned riding-type surface maintenance vehicle, the walk behind surface maintenance vehicle 20 includes variety of implements such as brushes and is capable of applying cleaning solutions. Again, loaded cleaning solution and other liquid material are usually removed by an articulated wiper assembly 90 located at rear of the surface maintenance vehicle 20. And again, such an articulated wiper assembly 90 is operatively connected to the surface maintenance vehicle 20 by a releasable attachment device 38 as described in more detail herein. The present invention, however, is concerned with releasably securing a portion of the cleaning assembly to these types of vehicles, and not the sweeping or other functional aspects of the vehicles. The particular surface maintenance vehicles illustrated in FIGS. 1 and 2 are thus relevant insofar as depicting the preferred environment with which the present invention is concerned.

#Referring to FIG. 3, the articulated wiper assembly 90 is operatively and releasably connected to the frame 22 of a surface maintenance machine 20 by an attachment device 38. The attachment device 38 includes a first component 40 having a mounting portion or plate 44 which is operatively connected to the surface maintenance vehicle 20 for vertical movement in order to raise and lower the articulated wiper assembly during cleaning operations and transport. Vertical movement of the articulated wiper assembly 90 may be accomplished via a variety of well known approaches such as hydraulic, pneumatic, electric, spring-biased, manually driven cables and/or gearing and the like (not shown). The mounting portion 44 may also “float” relative to the vehicle to enable the articulated wiper assembly to remain fully in contact with surfaces being cleaned, even though they are somewhat irregular or uneven. Additional elements of the attachment device 38 are disclosed herein.