Abstract:
A window washer control system and method administers fluid intermittently to a window based on an intermittent setting. A washer switch includes a plurality of frequency settings for varying a time interval between fluid administering events. The fluid level in a washer fluid reservoir is monitored to ensure a predetermined level. If the fluid level is below a predetermined level, control prevents intermittent washer administration and allows only manual activation.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to washer systems for windows, and more particularly to a washer system having an intermittent fluid delivery feature.  
       BACKGROUND OF THE INVENTION  
       [0002]     Automobile windows are exemplary of windows equipped with wiper systems for clearing a window, windshield and/or a rear window from rain, snow or other debris. Some wiper systems include an intermittent feature that allows the user to incorporate a time delay between wiper swipe events. Such a feature is convenient when swipe events are desired on a less than continuous basis. On some systems such as in vehicles, the time delay may be varied by the user according to driving conditions. For example, a long time delay may be desired for driving in light rain or snow. Similarly, a short time delay may be appropriate for driving in heavier precipitation.  
         [0003]     Typically, a wiper system includes a wash feature for administering wiper fluid onto the window in conjunction with a wiper swipe event. The wash feature is generally activated as a one time event upon operator request. As a result, an operator must observe the condition of the windshield or window on a continuous basis and initiate a wash event as needed. Often, while driving in unfavorable environmental conditions a wash event is needed on a regular basis. This condition is particularly apparent on the rear window of vans, sport utility vehicles and other vehicles having a generally upright rear window. Manual actuation of the wash feature in this situation is inconvenient.  
       SUMMARY OF THE INVENTION  
       [0004]     A washer control system and method delivers fluid intermittently. An intermittent operational mode is selected having a corresponding frequency of fluid delivery. Fluid is administered intermittently to the window based on the intermittent operational mode.  
         [0005]     In other features, the control system determines if a fluid level of a fluid reservoir is below a predetermined level. If the level is below the predetermined level, fluid administration is discontinued while in the intermittent setting.  
         [0006]     A method for administering fluid to a window determines an operating mode selected by the user from a range of operating modes. Fluid is administered to the window. A predetermined time is observed corresponding to the selected operating mode. Fluid is readministered to the window.  
         [0007]     In other features, intermittent fluid delivery is overridden based upon a request. A request may include instant fluid delivery or a delay in intermittent fluid delivery.  
         [0008]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]      FIG. 1  is a functional block diagram of a wiper control system according to the present invention;  
         [0011]      FIG. 2  is a representation of an exemplary wiper control switch according to the present invention;  
         [0012]      FIG. 3  is a representation of an exemplary washer control switch according to the present invention;  
         [0013]      FIG. 4  is a flow diagram illustrating steps for controlling the intermittent washer; and  
         [0014]      FIG. 5  is a flow diagram illustrating steps for providing a wash based on a frequency setting. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements  
         [0016]     Referring to  FIG. 1 , a window wiper control system  10  according to the present invention includes a wiper control module  14  and control stem  18 . The control stem  18  generally includes a manual wash control tab  20 , a wiper control switch  24  and a washer control switch  28  incorporated thereon. The wiper control switch  24  and the washer control switch  28  may comprise any type of switch suitable to communicate a range of inputs such as but not limited to a rheostat-type switch for example. The wiper control module  14  communicates with a fluid pump  30  disposed in a fluid reservoir  32  containing washer fluid. The pump  30  delivers washer fluid from the fluid reservoir  32  through fluid lines  36 ,  38  to respective front and rear spray nozzles  42 ,  44 . A front wiper assembly  46  includes wipers  48  pivotally coupled to wiper arms  50 . A rear wiper assembly  56  includes a wiper  58  pivotally coupled to a wiper arm  60 .  
         [0017]     The front spray nozzles  42  are located proximate to a front windshield  62  and may be mounted on a vehicle hood (not shown) or alternatively on the wipers  48  or wiper arms  50  of the front wiper assembly  46  for example. Similarly, the rear spray nozzle  44  is located proximate to a rear window  64  and may be mounted on a rear door (not shown) or alternatively on the wiper  58  or wiper arm  60  of the rear wiper assembly  56  for example. The front and rear spray nozzles  42 ,  44  are oriented to dispense washer fluid over a substantial viewing area of the respective front windshield  62  and rear window  64 .  
         [0018]     Turning now to  FIGS. 2 and 3 , the wiper control switch  24  and the washer control switch  28  will be described in greater detail. The wiper control switch  24  generally includes a moveable selector  68  for aligning with a desired operating condition. In general, the selector  68  is moveable to an off position  70 , a continuous position  72  and a range of intermittent positions  74 . The intermittent range  74  corresponds to intermittent wiping conditions having a range of selectable time delays.  
         [0019]     The washer control switch  28  generally includes a moveable selector  78  for aligning with a desired operating condition. In general, the selector  78  is moveable to an off position  80 , a continuous position  82  and a range of intermittent positions  84 . The intermittent range  84  corresponds to intermittent washing conditions having a range of selectable time delays. Skilled artisans will readily appreciate that alternative control switches may be employed for the wiper and/or washer control for communicating a desired condition to the wiper control module  14 .  
         [0020]     The wiper control system  10  of the present invention allows an operator to select a desired time interval or frequency for fluid delivery. In this way, movement of the selector  78  along the intermittent range  84  modifies a time delay between fluid administering events. The available time delays may range from every 30 seconds to every 20 minutes for example. It is appreciated that other time delays may similarly employed in relation to the intermittent range  84 .  
         [0021]     While operating in an intermittent wash condition, the control system  10  will also allow manual fluid delivery on demand through actuation of the manual wash control tab  20 . In this way, an operator desiring an immediate fluid delivery while in an intermittent setting may override the time delay associated with the intermittent setting. Furthermore, the control system  10  will also delay fluid delivery while in the intermittent setting based on a user input or other input such as an environmental condition.  
         [0022]     While operating in an intermittent wash setting, the control system  10  ensures the fluid level in the fluid reservoir  32  does not drop below a predetermined setting. Preferably, between wash events and during the time delay control verifies that the fluid level remains sufficient to provide fluid on a needed basis until the reservoir  32  may be replenished by the operator. The predetermined level may be set to 20 percent of full reservoir capacity for example. If the level drops below the predetermined setting, control activates a telltale on the instrument cluster (not shown) identifying low washer fluid level. When the telltale is actuated, fluid will not be administered while in an intermittent setting and can only be delivered manually through wash control tab  20 .  
         [0023]     Turning now to  FIGS. 4 and 5 , steps for operating a window wiper control system according to the present invention are shown generally at  100 . For simplicity, operation of the control system will be described as it relates to operation with the rear window  64 . It is appreciated however that the intermittent washing feature may be similarly employed for use with the front windshield  62 . Control begins with step  102 . In step  104 , control determines whether the washer switch  28  is set to the off position  80 . If yes, control ends in step  108 . If control is not set to the off position  80 , control determines if the washer switch  28  is set to the continuous position  82  in step  110 . If yes, control determines if a user requests a wash in step  114 . If yes, control commands fluid delivery in step  118 . If a user does not request a wash, control loops to step  104 . If control determines that the washer switch  28  is not set to the continuous position  82  in step  110 , a frequency setting is determined in step  126 . An intermittent wash is provided in step  130 , as will be described in greater detail, and control loops to step  104 .  
         [0024]     With particular reference now to  FIG. 5 , intermittent wash control  130  will be described. Control begins with step  200 . In step  204 , a timer is set to 1. In step  210  control determines if an override has been requested. If yes, control commands instant fluid delivery or delays fluid delivery based on the override in step  214  and control loops to step  210 . If an override is not requested in step  210 , control determines if the timer equals a frequency setting selected from the intermittent range  84  on the washer control switch  28  in step  218 . If not, the timer is incremented in step  220  and control loops to step  210 . If the timer equals the frequency setting, fluid level is determined in the fluid reservoir  32  in step  230 . In step  236 , control determines if the reservoir level is below a predetermined setting. If the fluid level is below a predetermined level, a telltale is signaled in step  240  and control ends in step  250 . If fluid level is not below a predetermined setting, control commands fluid delivery in step  248  and control ends at  250 .  
         [0025]     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. For example, the continuous setting  82  available on the washer control switch  28  may be eliminated. In addition, the intermittent feature available with respect to the washer control switch  28  may alternatively be incorporated on an in-dash switch for example exclusively assigned to a predetermined window. The in-dash switch may also incorporate a manual wash button similar to that described with respect to the manual wash control tab  20 . It is envisioned that an in-dash washer switch may be used in conjunction with the washer switch  28  on the control stem  18  such that each switch may be assigned exclusively to one of respective windows  62 ,  64 . Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.