Abstract:
A windshield wiper blade assembly having a plurality of wiper strips on a support, one of the wiper strips being normally positioned to engage a windshield while leaving non-engaged the remainder of the plurality of wiper strips, and rotation means for moving the engaged strip to a non-engaging position and for individually moving another of the plurality of the wiper strips to an engaged position.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a windshield wiper assembly having multiple separately activated wiper strips. 
   Windshield wipers generally consist of a metallic portion which carries a wiper strip generally made of a resilient material such as rubber and the like. The metallic portion is attached to a wiper rod which connects to a control inside the vehicle for activating the wiper and cause it to move so that the strip which is in contact with the windshield will oscillate and clear the windshield from rain, snow, dirt and the like. 
   Reportedly, 20 percent of all vehicle accidents result from impaired vision caused by dirty and/or damp windshields. It has been estimated by the industry that 50 percent of the windshield wiper strips on operational vehicles are beyond their functional life span. In general, wiper strips should be inspected every six months and replaced as soon as they diminish windshield visibility. Vehicle manufacturers typically recommend replacing strips every 6 to 12 months; in fact, wiper strips are such vital safety components that many European countries have laws that require replacing them every 12 months. 
   In the United States, while almost all states require vehicle inspections, there is seldom any serious testing as to the suitable operability of windshield wiper strips. In addition, most vehicle owners only notice that strips need to be replaced when they are already in a hazardous situation requiring new blades, i.e., during thunderstorms, snow storms, foggy days and nights, and the like. Few people, if any, have replacement strips or blades available at such times. Further, few, if any, have the knowledge and/or tools that may be required to replace the wiper or strip. 
   The problem is made worse by the fact that people are often far from their homes when such emergencies occur and do not know where to find a store carrying replacement parts. Often they occur at times when stores having replacement blades are not open. While garages may be open, most do not carry full lines of replacement blades or strips for every vehicle. For example, for most passenger cars, the blade length varies between 16 and 28 inches; and some newer vehicles have different length blades on each side of the windshield. In short, replacing the wiper blades or strips may not be possible in hazardous situations because of the impossibility of getting a replacement at that time. 
   While there have been many efforts to improve the performance of wiper strips, the fact remains that every wiper strip will, over time, become non-functional and need replacement. 
   The present invention overcomes the problems of the prior art by providing wiper blade assemblies having multiple wiper strips that are individually selectable to clear the windshield. A new wiper strip can be put into an operative position in contact with the windshield without removing the non-functional wiper strip or replacing the metallic portion carrying the strip. Thus, a vehicle operator who is faced with a situation requiring a new wiper strip can, as described more fully below, simply disengage the active wiper strip and engage a new wiper strip that already exists on the windshield wiper assembly. 
   SUMMARY OF THE INVENTION 
   Briefly stated, the present invention comprises a windshield wiper blade assembly comprising:
         a) A plurality of wiper strips mounted on an elongated support, one of said wiper strips being normally positioned to engage a windshield while leaving non-engaged the remainder of said plurality; and   b) rotation means for moving the engaged wiper strip to a non-engaging position and for individually moving another of said plurality of wiper strips to an engaged position.       

   The invention also comprises a windshield wiper assembly comprising:
         a) a housing and a plurality of wiper strips mounted on a rotatable longitudinal support at pre-established positions, said housing having a longitudinal slit such that one of said wiper strips may protrude beyond said housing to engage a windshield, thereby leaving the remainder of said plurality in a non-engaging position within said housing; and   b) wherein rotation of said rotatable longitudinal support moves the engaged wiper strip to a non-engaging position while moving a non-engaged wiper strip to an engaged position.       

   The invention also includes a method of selecting any one of a plurality of wiper strips to contact and clean a windshield comprising:
         a) mounting at least two wiper strips on an elongated supporting member;   b) disposing said supporting member adjacent a vehicle windshield so that one of said wiper strips normally is in engagement with said windshield; and   c) rotating at least a part of said supporting member to disengage said one of said wiper strips from engagement with said windshield and engaging another of said strips with said windshield.       

   OBJECTS AND FEATURES OF THE INVENTION 
   It is one general object of the invention to improve windshield wipers. 
   It is another object of the invention to facilitate replacement of an active windshield wiper strip with another windshield wiper strip. 
   Accordingly, in accordance with one feature of the invention, a plurality of windshield wiper strips are individually mounted on an elongated wiper strip support, thereby facilitating individual selection thereof. 
   In accordance with another feature of the invention, in one embodiment the elongated wiper strip support and mounted wiper strips are enclosed in a cylinder, thereby providing protection for such support and strips. 
   In accordance with yet another feature of the invention, the wiper strip support is partially rotatable, thereby facilitating selection and replacement of the strip desired for operational use. 
   In accordance with yet another feature of the invention, a longitudinal slit is provided in the aforementioned cylinder, thereby to provide an aperture through which the operational strip is partially extended when in use. 
   In accordance with still another feature of the invention, provision is made for partially rotating the wiper strip support to position a selected strip adjacent the aforementioned longitudinal slit so that a part of the selected strip will project outwardly through the slit to engage an adjacent windshield. 
   In accordance with yet another feature of the invention, provision is made for partially rotating the elongated wiper strip support manually, thereby facilitating selection of the desired strip for operational use. 
   In accordance with another feature of the invention, the wiper strip support is made effectively flexible, thereby facilitating flexure of the wiper blade to conform to curvature of the adjacent windshield. 
   In accordance with an optional feature of the invention, the wiper strip support is comprised of resilient material, thus facilitating flexure. 
   In accordance with another optional feature of the invention, the wiper strip support is comprised of a number of interconnected segments, thus facilitating effective flexure thereof. 
   In accordance with an optional feature of the invention, one of the wiper strips is designated as a dedicated sponge washer blade and optional fluid distribution is associated therewith, thereby facilitating cleaning of a windshield. 
   In accordance with another feature of the invention, provision is made for including wiper strips of differing characteristics, thereby facilitating improved performance under differing weather conditions. 
   In accordance with still a further feature of the invention, there may be included a warming system for warming windshield cleaning fluid, thereby preventing freezing and to assist in windshield de-icing. 
   In accordance yet an additional feature of the invention, optional provision is made for including a heating coil in the aforementioned protective cylinder, thereby to keep the wiper strips flexible despite cold weather and, 
   In accordance with another feature of the invention, in manually-operated embodiments, a hinged wing nut or an optional dial may be provided to facilitate the aforementioned partial rotation of the partially rotatable elongated support. 
   These and other objects and features will be apparent from the following detailed description of a preferred embodiment with reference to the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevation view of one preferred embodiment of the invention depicting an assembly according to the invention mounted on a conventional reciprocating windshield wiper arm; 
       FIG. 1A  is a side elevation view of an embodiment generally similar to that of  FIG. 1  except including a dial instead of a wing-nut, a unitary longitudinal wiper strip support instead of a support comprised of a large number of segments and including a narrow supporting frame instead of an enclosed housing; 
       FIG. 1B  is an end view of a prior art wiper blade having flex characteristics suitable for use herein with minor modifications; 
       FIG. 2  is a side elevation view of another preferred embodiment which is generally similar to that of  FIG. 1  but additionally includes curved end caps and shows a partial section to facilitate illustration of an internal partially rotatable subassembly; 
       FIG. 2A  is a side elevation depicting the left end cap of  FIG. 2 ; 
       FIG. 2B  is an inner end view of the cap of  FIG. 2A ; 
       FIG. 2C  is an inner end view of the cap of  FIG. 2D ; 
       FIG. 2D  is is a side elevation depicting the right end cap of  FIG. 2 ; 
       FIG. 3  is a section view of the center of  FIG. 2 ; 
       FIG. 3A  is a view similar to that of  FIG. 3  except for illustrating an optional embodiment that includes both a wiper strip and an adjacent sponge; 
       FIG. 4  is a section view of the wiper strip support and wiper strips of  FIG. 1A  or an alternative center part of  FIG. 3 , and depicting more than two wiper strips; 
       FIG. 5  is a simplified view of the enclosed housing members of  FIGS. 1 and 2 ; 
       FIG. 6  is a left end view of the keeper member depicted in  FIG. 7 ; 
       FIG. 7  is a side elevation view of a keeper that may be included in the wiper assemblies of  FIGS. 1 and 2 ; 
       FIG. 8  is a right end view of the keeper member depicted in  FIG. 7 ; 
       FIG. 9  is a side view of a part of an operating rod assembly, the central rod of which extends longitudinally through the elongated wiper strip support members; 
       FIG. 10  is a section view taken along the section lines A-A of  FIG. 9 ; and 
       FIG. 11  is a right end view of  FIG. 9 . 
   

   DETAILED DESCRIPTION 
   While the windshield wipers of the present invention are suitable for use on a variety of vehicles or crafts such as automobiles, trucks, motorcycles, boats, trains and the like where windshield wipers are used, the present invention will be further described in connection with automobiles. Further, it is to be noted that while manufacturers use different means to attach their windshield wiper blades to reciprocatable arms of windshield wiper assemblies, the present invention is suitable for use with a variety of supporting and activating mechanisms including (but not limited to) universal adapters for support and/or attachment in a wide variety of different installations used by various manufacturers. 
   Moreover, the present wiper blades may be made using a variety of materials. Thus, the metallic portion, or frame, may be made of any of the conventional spring materials such as steel, flexible plastics, or a combination of metal and flexible plastic; and the wiper strip can be made of rubber or other flexible materials having the desired qualities. Furthermore, it should be evident that basic architecture of the frame of the wiper blade can be conventional as presently employed in existing wiper systems, or it can be modified, provided that it is effective to exert sufficient pressure on the wiper strip to keep it in the desired engagement with the adjacent windshield surface despite wind or other conventional forces that may be encountered at highway speeds. 
   As mentioned above, one of the features of the preferred embodiments is that the present invention facilitates different types of wiper strips to be included on the wiper blade support for use in different weather conditions. Thus, for example, a brush assembly can be utilized in place of or with a flexible rubber or rubber-like strip for use in snowy conditions; a sponge may be employed under some conditions; or double-bladed wiper strips such as those of U.S. Pat. No. 3,939,524 can be used in heavy downpours. In short, the plurality of strips can be the same or different to permit the driver to utilize as the active wiper that which is most effective to clear the windshield under the weather conditions encountered. 
   Details of present invention will now be further described in connection with the embodiments shown in  FIGS. 1 ,  1 A and  2 . Before proceeding further, however, it may be helpful to note one of the principal differences between the embodiments. As will be evident from the following description, it is very important that the selected wiper strip be in effective contact with the adjacent windshield when in use. Therefore, provision needs to be made to compensate for windshield curvature. So as to maintain a selected wiper strip in effective contact with the adjacent windshield, the wiper strip needs to be resilient, and it&#39;s support needs to be responsive to applied pressure to effect a compensating curvature. The latter is accomplished in  FIGS. 1 and 2  by segmenting the wiper strip support into a relatively large number of semi-coaxial segments while providing small lateral spaces therebetween so that the central axes of the wiper strip support segments (hereinafter called “keepers”) can vary modestly with respect to each other and become non-coaxial to the extent necessary to maintain the wiper strips in desired contact with the windshield. Compensation for windshield curvature is provided for in the embodiment of  FIG. 1A  by replacing the segments with an essentially homogeneous support that is flexible and mounted on a central rod that is also flexible, thus resulting in essential wiper blade conformity to windshield curvature. 
   Now turning to  FIG. 1 , it will be seen that there is therein depicted a wiper blade assembly  10  comprising an oval protective housing  11  and a wiper strip assembly  12  similar to that of  FIG. 2 . Assembly  12  includes a wing nut  13  for partially rotating a flexible rod  14  ( FIG. 9 ) that passes through wiper strip support  15  ( FIG. 3 ) to which wiper strips  16  and  17  are attached. As will be evident from the following description, support  15  in the embodiments of  FIGS. 1 and 2  is comprised of a plurality of keeper segments, whereas in the embodiment of  FIG. 1A , it preferably is a non-segmented cylindrically shaped resilient member. 
   The protective housing  11  is preferably attached to a conventional reciprocatable wiper arm  18  by resilient frame members such as members  18   a - 18   d , thus causing housing  11  to move correspondingly to movement of arm  18 . Members  18   a - 18   d  preferably act as springs to impart desired pressure to keep the operative wiper strip  16  in contact with the adjacent windshield. Arm  18  may, of course, be activated by a switch or another conventional activating device usually located in the interior of the vehicle. 
   Protective housing  11  may be made of any of a variety of conventional materials that preferably are relatively light and impact resistant. Thus, it may be made of material such as steel, aluminum or impact resistant plastic, and it is structured to conduct suitable pressure to the then active wiper blade strip (e.g., strip  16 ) to maintain it in desired contact with the adjacent windshield to provide effective removal of moisture and the like. 
   Left end  20  and right end  21  of protective housing  11  include openings  20   a  and  21   a  through which rod end portions  14   a  and  14   b  protrude. End portion  14   a  is preferably threaded to receive rotator wing nut  13  which, as shown in  FIG. 9 , includes folding wings  13   a  and  13   b  together with hinges  13   c  and  13   d . The wing nut helps maintain the shaft  14  in proper relationship to frame  11  and also provides a way for a user to turn the shaft so that a selected wiper strip (e.g., strip  15  or  16 ) is put in contact with the windshield. As shown in  FIGS. 1 and 2 , wiper  16  is the active wiper in contact with the vehicle windshield. 
   It should be noted in connection with both  FIGS. 1 and 2 , that although in the preferred embodiments, the rod  14  ( FIG. 9 ) extends all the way from left end  14   a  to right end  14   b  it could be discontinuous. If discontinuous, operative turning torque may be progressively communicated through the mounting assembly by the engagement of tabs such as tabs  30   c  and  30   d  ( FIG. 8 ) with mating recesses such as recesses  30   b  and  30   a  ( FIG. 6 ) on the adjacent keeper. 
   In the embodiments herein depicted, rod  14  is depicted as being continuous and having an essentially square cross section over its center portion ( FIGS. 2 ,  3 ,  3 A,  4 ,  6 ,  8  and  10 ), thus acting to impart turning forces to the mounting assemblies in addition to turning forces communicated by keeper tabs and adjoining mating slots. However, it should be understood that for the embodiments that employ keepers ( FIGS. 1 and 2 ), it could be made circular or oval in cross section since sufficient turning torque is communicated through the tabs and slots. 
   Referring further to  FIGS. 1 and 2 , keepers  19   a  and  19   b  are interconnected by a series of similar keepers through which turning forces are communicated by rod  14  and/or the connecting tabs/slots. In this respect, it should be noted that sufficient space is provided adjacent the keepers (e.g., spaces  24   a  and  24   b  to permit the above-mentioned flexing and fit of the associated wiper blade strip to conform to the curvature of the adjacent windshield. 
   Referring again to  FIG. 9 , it will be observed that wings  13   a  and  13   b  can be folded out of the way when rotator wing nut  13  is not being utilized. Moreover, it will be evident that wing nut  13  could be replaced by a dial such as dial  40  (shown in  FIG. 1A ) or other known and conventional devices to provide for partial rotation of shaft  14  to change the wiper strip contacting the vehicle windshield. 
   As will now be evident, the protective housing  11  surrounding wiper strip assembly  12  additionally acts as a protective covering to shield the wiper strip assembly  12  and the wiper strip or strips that are not in use. Thus, the non-active strips are protected from weathering and damage from ultra-violet radiation. Of course, such protection could be provided by one or more individual wiper covers such as those offered by Intromark, Inc., of Pittsburgh, Pa. 
   Reference again to  FIGS. 2 and 3  reveals inclusion of a longitudinal horizontal opening such as slit  22  through which the currently active wiper strip (e.g., wiper strip  16 ) protrudes to contact the vehicle windshield. Passive wiper strip  17  is safely protected by housing  11  until shaft  14  is partially rotated so that strip  17  protrudes through opening  22  to become the active wiper strip. As previously mentioned housing  11  acts to ensure that passive wiper strip(s) are not exposed to ultra violet radiation and the other degrading environmental conditions. 
   Further reference to  FIG. 2  reveals that it depicts a wiper assembly similar to that of  FIG. 1  except for protective end caps  11   a  and  11   b  which are depicted in  FIGS. 2A ,  2 B,  2 C and  2 D. 
   As mentioned previously, one of the desired characteristics of the wiper strips is that they be made of resilient material. This is not only so that the strip conforms to a modest curvature of the adjacent windshield but also to provide for it to bend so that it can be retracted into housing  11  when rod  14  is turned to present another strip as the active strip. From  FIG. 3 , it will be evident that there is provided a substantial clearance  23  between the outer surface of wiper strip support member  15  and the adjacent inner surface of oval housing  11 . Thus, when rod  14  is partially rotated, longitudinal force is imparted to the active wiper strip (e.g. strip  16  in  FIG. 3 ) to bend it sideways to retract it from slit  22 . If the rod  14  is turned further, the next strip (e.g., strip  17  in  FIG. 3 ) comes into position at slit  22 , whereupon its resiliency projects it outwardly therethrough to assume the position shown for strip  16 . 
   While the wiper strip assemblies of  FIGS. 1 and 2  include only 2 wiper strips (i.e., strips  16  and  17 ),  FIG. 4  depicts a wiper blade assembly  12   a  having 3 wiper strips  25 ,  26  and  27 . Such assembly  12   a  is similar to assembly  12  of  FIG. 3  and its operation is similar to that described above. Housing  11  is not shown in  FIG. 4  since the assembly of  FIG. 4  may be employed with the embodiment of  FIG. 1A  in which the housing is eliminated; but where a housing is provided (as with the assemblies of  FIGS. 1 and 2 ), operation would be similar to that of  FIG. 3 . It should again be noted that, as mentioned above, as an alternative to protection provided by housing  11 , each of the non-active wiper strips of assembly  12   a  can be covered with a removable plastic covering preferably an environmentally-resistant plastic material such as that offered by Intromark, Inc., of Pittsburgh, Pa. Such plastic materials are well known and are made of UV and mildew resistant plastics. To illustrate this, a part  27   a  of a protective covering for wiper strip  27  is shown on the right surface of wiper strip  27 . When the active wiper strip is to be changed, the replacement passive wiper strip is simply rotated to a position to contact the windshield and the plastic covering for that wiper is removed. 
   It should be evident that even for an embodiment in which only one wiper strip at a time is operative, more than 3 wiper strips can be placed onto a support, provided that they be spaced sufficiently far apart so that only one strip contacts the windshield and that the passive strips do not interfere with the action thereof. This spacing can be readily determined by routine experimentation. It should also be evident that more than one slit (such as slit  22 ) could be provided. Thus, a pair of closely spaced parallel slits could be employed (or a single slot widened as shown in  FIG. 3A ) so that two strips could be activated simultaneously. Accordingly, a pair of strips with different characteristics could be activated. As an example, one such strip could be made of water-retentive material, e.g., sponge, and another could be made of conventional wiper material, thus facilitating the cleaning of a particularly dirty windshield. Such is shown in  FIG. 3A  which is seen to be very similar to  FIG. 3  except for inclusion of sponge member  16   a  and the enlargement of slit  22  to accommodate both wiper strip  16  and sponge  16   a.    
   Reference is now made to  FIG. 5  which, as mentioned above, is a simplified view of the enclosed housing members of  FIGS. 1 and 2  emphasizing their essentially tubular geometry. 
   Reference is next made to  FIGS. 6-8  that depict a representative one of the plurality of keepers  19  (including, e.g., keepers  19   a ,  19   b  and  19   c  of  FIG. 1 ) that are included within housing  11 . As mentioned above, the purpose of the keepers is collectively to act as a functionally flexible support for the wiper strips. When interconnected (as they are for  FIGS. 1 and 2 ), they collectively act as a mounting support for the wiper strips. 
   Referring additionally to  FIG. 6  that, as mentioned above, is a left end view of one of the representative keepers, e.g., the keeper of  FIG. 7 , it will be observed that the keeper  19  is essentially cylindrical and circular in cross section. However, spaced about its periphery are four items  30   a ,  30   b ,  31   a  and  31   b . Two of these (namely  31   a  and  31   b ) provide slots into which shank portions of the wiper strips (e.g., shank portion  32  of  FIG. 3 ) are inserted. The remaining two, i.e., recesses  30   a  and  30   b  accept tabs (such as tabs  30   c  and  30   d  of  FIG. 8 ) that extend from the next (adjacent) keeper. In this connection, it should be noted that tab  30   d  lies behind tab  30   c  in  FIG. 7  and is displaced peripherally 180 degrees therefrom. Thus, it does not separately appear in  FIG. 7 . 
   As will be apparent from the foregoing, the mating of recesses and tabs is such that when the keepers are assembled, angular movement of wing nut  13  or dial  40  results in a like angular movement of the keepers. 
   As mentioned above,  FIG. 7  is a side elevation view of representative keeper  19 . There, it will be observed is tab  30   c  which will be inserted into recess  30   b  in the adjacent keeper and which is non-circular (preferably rectangular) in cross section so as to conduct turning torque therebetween. 
   As mentioned above,  FIG. 8  is a right end view of keeper  19  of  FIG. 7 . There, in  FIG. 8 , are the wiper strip slots  31   a  and  31   b , tabs  30   c  and  30   d , and central recess  33  into which the center shaft  14  will project. 
   Now turning to the embodiment of  FIG. 1A , it will be seen to be a side elevation view of an embodiment generally similar to that of  FIG. 1  except including a dial  40  instead of wing-nut  13 , a unitary longitudinal wiper strip support  12   a  (see also  FIG. 4 ) instead of the segmented supports of  FIGS. 1 and 2 , and a narrow supporting frame  41  instead of an enclosed housing. Frame  41  is generally u-shaped and includes central member  41   a  together with left and right end members  41   b  and  41   c . Further reference to  FIG. 1A  reveals that the wiper arm actuating assembly  18  is similar to that of  FIGS. 1 and 2 . The assembly of  FIG. 1A  employs a rod  14  the ends of which project outwardly from support  12   a  and identified by symbols  14   a  and  14   b . Support  12   a  and the associated wiper strips are as shown and described with respect to  FIG. 4 . As will be obvious from an examination of  FIGS. 1A and 4 , rotation of dial  40  results in the selection of the active wiper strip as between strips  25 ,  26  and  27 . 
   Referring again now to  FIG. 9 , it will be observed to be a side view of part of the operating rod assembly, the central rod  14  of which, when assembled, extends longitudinally through the elongated wiper strip support member ( 12  in  FIGS. 1 and 2 , and  12 A in  FIG. 1A ). There, in  FIG. 9 , is partially threaded rod  14  of which the central part is preferably square or rectangular in cross section as shown in  FIG. 10 , (although it may be circular or oval as mentioned above); wing nut  13  (provided to manually impart angular movement to rod  14 ); cylindrical washer  36 ; and circular end  14   b  which is shown in  FIG. 11 . 
   Assembly is accomplished by attaching end cap  11   b  to housing  11  ( FIG. 2 ); next, sliding keepers  19  onto rod  14 ; next sliding wiper strips  16 ,  17  or  25 - 27  into mating slots (e.g., slots  31   a - 31   b ) while maintaining the keeper slots  31   a - 31   b  in alignment, thus creating a sub-assembly; next, inserting the sub-assembly into the protective housing  11  so that a selected wiper strip extends outwardly through slit  22  and the end  14   b  of rod  14  extends through the opening  21   a  in right end member  21 ; next, attach end cap  11   a  to housing  11  while aligning and projecting the left end  14   a  of rod  14  through mating aperture  11   c  of end cap  11   a ; and then attaching wing nut  13  to the projecting threaded part of rod  14 . 
   It will now be evident that there has been disclosed herein an improved windshield wiper blade assembly that facilitates timely and effective replacement of wiper strips. Although the invention hereof has been described by say of example of preferred embodiments, it will be evident that other adaptations and modifications may be employed without departing from the spirit and scope thereof. 
   The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of the invention.