You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the filing date of earlier filed provisional application Ser. No. 60/820,530 of Jul. 27, 2006, entitled LIQUID SPREADER FOR DE-ICING SIDEWALKS AND STEPS, and which application is hereby incorporated by reference in its entirety. 
     
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a device for liquid de-icer application, specifically designed for winter use, making it more suitable for use in de-icing as opposed to simply using general use agricultural sprayers. 
       BACKGROUND OF THE INVENTION 
       [0003]    The use of liquid de-icer compositions is known. Some prefer liquid de-icers over solid form pellets, since liquids have unique melting properties and spread easier than dry products. However, the application process for liquid de-icers can often be difficult for the operator. Currently application methods center around use of heavy manual pump fertilizer sprayers, carried in one hand or carried in a back harness, and applied with a hand wand. These are not satisfactory for winter use for a variety of reasons. The operator needs to stop regularly to repump the sprayer. They also have capacity and weight issues, making this unappealing, particularly in the winter when standing in the cold, on ice. Even further compounding the problem is that liquid de-icer chemicals are heavy, typically running eleven or more pounds per gallon. This makes wand application over long stretches of sidewalk or driveways difficult and tiring. 
         [0004]    In order to overcome these deficiencies, there have been some efforts at developing mobile sprayers for de-icing sidewalks and steps that may be pushed like a lawn mower while using battery powered spray systems. People trying this approach have simply turned to lawn and garden sprayers mounted much like an engine is mounted on a hand push lawn mower chassis. However, there are certain design and environmental condition requirements encountered by de-icing spray systems in the wintertime that simply make adaptation of a conventional lawn mower chassis to de-icer spray system using a tank, ill-suited for best de-icer needs. 
         [0005]    Among the problems that occur are those resulting from the winter conditions, the weight of the de-icer, and metal corrosion. With the goal of the sprayer to be easily maneuvered on ice and snow covered paved areas for controlled spray patterns, there is a need to address the proper arrangement necessary to achieve this; at the same time there must be some sort of braking system to allow one to let the unit sit motionless while acting as a pump station to power a spray wand use. The operator must be confident that it will not simply roll away on an inclined or icy surface. 
         [0006]    Moreover, additional problems are found with the spray bar that is typically used in the front of mobile sprayers, such as agricultural sprayers. It often gets in the way, either because it is not needed for the particular application, or it is needed in a slightly different configuration than a fixed bar, which is typical. There is therefore a need for a collapsible spray boom hinged in two points off the front corners of the de-icer sprayer chassis which may expand or unfold like wings of a folding tool bar. It can then be selectively and independently moved from an operable position to an inoperable position or anywhere in between. 
         [0007]    Another problem with conventional agricultural use sprayers using hand wands is an erratic spray pattern, meaning that some areas get skipped. There is a need for a unit that therefore has both adjustable spray booms for uniform application and as optional for the user, a hand wand to get at difficult places not reachable by the booms. 
         [0008]    Another difficulty sometimes encountered with a lawn mower-type chassis that has spray booms attached to the front is that the booms themselves can get in the way; they therefore need to be selectively moveable from operational or extended positions to non-operable collapsed, storage positions. 
         [0009]    Yet another issue with conventional agricultural sprayers when used for de-icers is that the pump system must be shielded and isolated from the often difficult environmental conditions such as moisture, corrosive effects of de-icer salts, and snow and ice that may cause pump operation difficulties. 
         [0010]    Another need is to have a mobile unit which can have an easily removed quick change tank with a push/pull connection and one which has the hose and pumping system, as well as its electrical system all operating under cover, protected from the difficult winter environment. 
         [0011]    The solving of the above problems and needs, specific to de-icer application systems, as opposed to using boomed agricultural systems, portable pump sprayers or backpacks can be achieved by use of the system of the present invention. It uses alternately and selectively in combination collapsible wing sprayers, the use of a hand held wand, the use of a chassis brake, environmentally protected power and pump components, and a quick change with a push/pull connection tank. The invention therefore addresses these specific needs and perhaps others, all unique to de-icer spray systems, as opposed to conventional lawn and garden sprayers. It therefore can be seen that the invention solves the stated problems and needs and represents an advance and improvement for the de-icing industry. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    A liquid de-icer applicator which is specifically designed for convenient de-icer application, as opposed to modifying an agricultural spray. The unit has a generally horizontal rigid chassis with an attached push handle, a tank detachably mounted on the chassis for holding and dispensing liquid de-icer, one or more adjustable wing spray bars mounted to the chassis which can move from retracted or closed transport position to various operational positions. Adjustable wing spray bars are fluidly connected to a spray system which can be selectively operated at the spray bars and a set of fixed spray nozzles or by use of a hand wand. The applicator has a pair of spaced apart wheels mounted to allow convenient and balanced mobility. Finally, there is an associated power supply (battery) for operation of the spray system and it is all housed under a protective housing. Preferably the unit includes a control panel mounted on the push handle for control of the spray booms, and the spray itself. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of the de-icer application unit in perspective, with the quick change tank removed. 
           [0014]      FIG. 2  is a front view of the de-icer of  FIG. 1 . 
           [0015]      FIG. 3  is a rear view of the de-icer of  FIG. 1 . 
           [0016]      FIG. 4  is a side view of the de-icer, showing the side which holds the selectively usable spray wand. 
           [0017]      FIG. 5  is a top view of the de-icer of the present invention, with parts broken away to show the ports below the top cover. 
           [0018]      FIG. 6  is a schematic of valving and pump lines showing how the de-icer may be selectively distributed to the fixed front nozzles and those mounted on the spray bars, or to the hand held spray wand. 
           [0019]      FIG. 7  is a schematic of the electrical system of the unit. 
           [0020]      FIG. 8  shows the inlet plumbing subassembly and battery cover with its integral tube fittings. 
           [0021]      FIG. 9  shows the construction of the quick disconnect shown in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]      FIGS. 1-8  show a preferred embodiment of the present invention. It is understood that this preferred embodiment is illustrative only and that there are other embodiments that are fully intended to come within the scope of the attached claims. The Applicant therefore intends to rely fully upon the current state of the U.S. Patent Laws as of the time of this filing, including the doctrine of equivalents. It is within the spirit of this understanding that the detailed description is provided. It should also be mentioned that unit may be used to spray liquids other than de-icers, even though it is especially designed for that purpose. 
         [0023]    Referring to  FIG. 1 , there is shown in perspective a de-icer spray apparatus  10  which has a cowling or cover  12  which protects the covered battery, plumbing, circuitry and pump from the exterior weather environment. The de-icer  10  has a rigid chassis  14  having sides  16 ,  18 , and front  20  and rear  22 . The chassis  14  is supported by two rear wheels  24 ,  26  connected adjacent the rear end of the rigid chassis  14 . 
         [0024]    Pivotally mounted hubs at  21  and  23  to the sides  16 ,  18  of chassis  14  near the front  20  which connect to the side booms or side spray bars  28 ,  30 . Side spray bars  28  and  30  are snap fit mounted to rigid chassis so that they may be selectively moved between various open operable position ( FIG. 2 ) to a closed or retracted positions where they are parallel to, and underneath the chassis sides  16  and  18 . 
         [0025]    Mounted to each of the spray bars  28  and  30  are spray nozzles  32 ,  34  and similarly mounted are fixed spray nozzles  36 ,  38  on front  20  of chassis  14 . 
         [0026]    Bumper  40  is attached to the front of cowling  12  and pivotally mounted at  42 ,  44  to posts  46  and  48  attached to the front  20  of chassis  14 . It therefore can be seen that cowling  12  can be pivoted up and forward by pivot points  46 ,  48  to reveal the interior of the device  10 . 
         [0027]    Cowling or housing  12  has a central opening  50  for holding inert plastic (non-corrosive) de-icer tank  52 . De-icer tank  52  has a screw on lid  54  ( FIG. 8 ) with a quick hose connection for fluid line to diaphragm pump  60  resting in the forward front portion of compartment of the housing or cowling  12 , the bottom of which is defined by chassis  14 . Pump  60  pumps de-icer by a pump inlet  62  and feed tube  64 , and tank siphon tube  66  to the spray nozzles and wand. Pump  60  action is illustrated with the plumbing circuitry/solenoid valve operation combination in  FIG. 6  to demonstrate how fluid is transported to the spray nozzles.  FIG. 6  shows how de-icer from tank  52  may be directed selectively (depending on which way solenoid switches  68  and  70  operate) to selectively provide de-icer spray  72  to the boom nozzles  32 ,  34  and/or front nozzles  36 ,  38  or alternatively to hand wand  74  via trigger controlled manual valve  78 . 
         [0028]    The electrical schematic for selective operation of pump  60 , solenoids  68 ,  70  and valves for the nozzles  32 ,  34 ,  36  and  38  or hand wand  74  and user control housing  76  are shown in  FIGS. 6 and 7 . As can be seen, use of the control housing  76  through the appropriate electrical circuitry illustrated in  FIG. 7  will selectively operate pump  60  to pump fluid via solenoid operated valves  68  and  70  to nozzles of booms  32 ,  34  and front fixed nozzles  36  and  38  respectively, or alternatively, by trigger controlled manual valve  78  sending fluid from tank  52  directly to wand  74 . 
         [0029]    Lever  80  is moveable from a closed position ( FIG. 1 ) to an open position downwardly and forwardly which operates a boom control cable (not depicted) of conventional construction. It is a conventional flexible cable to selectively rotate boom  28  and  30  out into extended or operational position. This cable system allows the operator to selectively extend booms  28  and  30  to the fully extended position as shown in  FIG. 2  or something less than that by simple adjustment of lever  80  to accommodate or adjust for varying width sidewalks. As a result, the spray pattern width can be controlled as the operation continues. As illustrated in  FIG. 2 , both spray booms  28 ,  30  are selectively extended by use of lever  80 ; spray booms  28 ,  30  are correspondingly retracted moving in and closed underneath the chassis via the pivot connection earlier explained upon backward movement of lever  80 . Since the details of boom control via flexible cables to extend from extended or out position to in or retracted position are conventional, mechanical contrivances for adjustability well within the routine skill of the art, the specifics of those are not depicted herein. Hose  82  is connected to wand  74  to allow the wand  74  to be moved away from the unit  10  to selectively spray difficult to reach locations. Handle  84  is of conventional construction, is used for example on lawn mowers and may be collapsed via screw clamps  86 ,  88  for convenient storage. 
         [0030]    As best illustrated in  FIG. 4 , the chassis  14  has its associated set of chassis wheels  24 ,  26  conventionally mounted, but behind the center of gravity of tank  52  to provide a desired handle force for the operator. Stops  90  and  92  (see  FIG. 5 ) extend down from the chassis towards the ground to help reduce the tendency of the unit to roll on an incline and provide wear-resistance and balance when moved by an operator when dragging unit by wand hose or other action. 
         [0031]    Referring specifically to  FIGS. 6 and 7 , the following describes the preferred embodiment of the invention: 
         [0032]    The user control housing provides the user with a rotary knob  94  and a rotary trigger  96  (lever  96 ,  FIG. 1 ). The knob has internal cams that activate the switches shown in  FIG. 7 , and the knob  94  is provided with preferably 3 detent positions in its housing. For clarity, the detented positions may be referred to as OFF,  1 , and  2 . 
         [0033]    When the knob  94  is in the off position, no electrical power flows to the pump  60 , or to the two solenoid valves (# 1  and # 2  of  FIG. 7 ) (solenoid  68 ,  70  operated) shown in  FIG. 7 . When the knob is rotated to position  1 , cam switch # 1  closes, which provides power from the battery  58  to the pump  60  and to the trigger switch. At this point the pump  60  pressurizes the plumbing system in preparation for spraying. If desired, while the rotary knob is in position # 1 , the manual valve of the spray wand, located within the pistol grip portion of the wand, can be activated by the operator to cause fluid flow to the wand nozzle only. 
         [0034]    While the knob  94  is in position  1 , the trigger can be activated, which closes the trigger switch, which in turn opens valve # 1  which permits fluid to flow to the fixed nozzles  36 ,  38  only. In this embodiment, this allows the operator to spray a narrow pattern, without deicer waste, or application of excessive amounts of de-icer to the desired area. 
         [0035]    When the rotary knob  94  is moved to position # 2 , cam switch # 2  is closed. Under this condition, when the trigger is activated, and the trigger switch is closed, valves  1  and  2  are activated which causes fluid to flow to nozzles  38 ,  40 , and  32  and  34 . 
         [0036]    An alternative embodiment is wherein all valves can be activated when the rotary knob is in position  1 , thereby reducing the necessary knob positions to just OFF and  1 . As such, valves  1  and  2  can then be replaced by a single valve of appropriate size, if desirable. 
         [0037]    An additional alternate embodiment might entail moving cam switch # 2  so that it is activated by the boom control lever. In such an arrangement, cam switch # 2  would be activated only when the booms have been moved from the parked position. This would effectively prevent the boom nozzles from spraying while fully retracted, and would thereby allow the same functionality as the preferred embodiment by a different method. 
         [0038]    In the preferred embodiment, the recharge port ( FIG. 7 ) is designed so that when the plug from the recharging device is inserted into the recharger port, all of the electrical devices (pump, valves, and switches) are electrically isolated from the battery. This is to prevent damage to the recharger and/or any of the electrical devices on the unit. In addition, the isolation of the switches prevents inadvertent spraying should the operator activate the trigger during the recharging process. 
         [0039]    The details of the quick disconnect shown in  FIG. 8  at  56 , are shown in  FIG. 9 . The quick disconnect  56  can simply be pulled apart to disconnect the fluid hose of the detachable tank assembly from the battery cover  59 , with its integral tube fitting  98 . As can be seen in  FIG. 9 , there is a double O-ring for insertion—removal and release allowing a tool free and screw action free method of removing empty tank from system. Thus, should the user forget to disconnect the inlet assembly ( FIG. 9 ) when the tank  52  is removed, it simply pulls the connection apart without damage. 
         [0040]    In actual operation, the unit works in the following manner. Tank  52  is filled with liquid de-icer loaded into and connected to plumbing of unit  10 . The unit is switched on, by rotary knob  94  on control housing  76 , meaning battery  58  is electrically connected to allow pump  60  to be in operable position and the circuit of  FIG. 6 . Lever  80  is moved to the desired position so that spray boom arms  28  and  30  are extended such as illustrated in  FIG. 2  and trigger  96  is closed by the operator to open appropriate valves via solenoids  68  and  70  to allow de-icer to be pumped to spray nozzles  32 ,  34 ,  36  and  38  as determined by position of  94  or other desired positions via pump  60 . As a result, since the battery  58  energizes pump  60  when  94  is moved to 1 or 2 position, spray is delivered to by nozzles  32 ,  34 ,  36  and  38  in front of the unit  10  as determined by position of knob  94 . If spraying is desired to be stopped, trigger  96  is released from its depressed state opening the circuit, closing valves ( FIG. 7 ) via solenoid  68  and  70  and stopping the spray. 
         [0041]    Similarly, if one desires to dispense spray via hand wand  74 , wand valve  78  is manually opened to allow flow of spray from pump  60  out of wand  74  by way of hose  82 . If the unit is desired for storage, lever  80  is pulled back and booms  28  and  30  retracted, handle  84  may be collapsed, tank  52  removed (if desired) and the unit stored. 
         [0042]    Boom height and location relative to the ground surface have been selected to prevent spray drift from the nozzles  32 ,  34 ,  36  and  38  while still providing desired spray pattern and rate of application. In particular, they have been optimized for balance of pattern, rate, overspray and droplet size, impact, velocity, etc. 
         [0043]    Worthy of note is the preferred molded plastic construction of the base and cover and boom mechanics, so that the device  10  will survive in a de-icer environment. There has been outlined in the specification, rather broadly, the more important features of the invention in order that its details may be better understood and appreciated for the present contribution to the art. It is to be understood, however, the invention is not limited in application to the precise details and construction arrangements here set forth, but that modifications can be made to provide other various combinations still achieving the objectives of the present invention. It is also to be realized that optimal dimensional relationships for the parts mentioned to function include variations in size, materials, shape, form, function, and that a variety of different physical components may be used for each of the separate individual elements here described. 
         [0044]    With the above foregoing description of a preferred embodiment in mind and the description of the essential features set forth the invention is claimed as follows:

Summary:
A liquid de-icer applicator which is specifically designed for convenient de-icer application, as opposed to simple agricultural spray. The unit has a horizontal frame chassis with an attached push handle, a tank detachably mounted on the chassis for holding and dispensing liquid de-icer, a pair of foldable wing spray bars mounted to the front of the chassis which can move from folded or closed transport position to operational positions. The foldable wing spray bars are fluidly connected to a spray system which can be selectively operated at the spray bars or by use of a wand. The applicator has a pair of spaced apart wheels mounted near the rear end of the chassis, behind and below the tank in order to allow convenient and balanced mobility. Finally, there is an associated power supply (battery) for operation of the spray system and it is all housed under a protective housing. Preferably the unit includes a control panel mounted on the push handle.