Patent Application
20070094831
This invention relates to a windshield wiper system for a vehicle or machine, and, more particularly, to a single windshield wiper system that can be used for all weather and environmental conditions.
Conventional windshield wiper systems employ a single wiper blade attached to a wiper arm assembly for clearing a windshield of water or condensation occurring during rain or fog. That single blade wiper works acceptably when used for clearing falling snow; however, it is ineffective for removing accumulated snow, ice and other debris. For example, when clearing a windshield of mud or dust, water is used causing the windshield to attract additional dust that is smeared on the windshield by the wiper blade. When clearing ice, the blade sometimes buckles or simply glides over patches of ice damaging the wiper blade material.
One approach to solving the problem of adequately clearing and cleaning the windshield uses a wiper with a blade that rotates to expose a different windshield contact material. When rain is the problem, a regular rubber or elastomeric blade is used, and when ice is the problem, the blade is rotated to expose a different, harder blade material. A problem with such a rotatable blade wiper system is that is requires the operator to manually rotate the wiper blade. Manual rotation must be accomplished from outside the vehicle requiring the operator to exit the vehicle which is not always possible or even practical. Accordingly, it will be appreciated that it would be highly desirable to have a windshield wiper system that can be easily used in any weather or environmental condition from inside the vehicle or machine.
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present the invention, a windshield wiper system comprises a wiper arm; a base member pivotally attached to the wiper arm; a first wiper blade assembly having a first wiper blade and being attached to the base member; a linkage assembly attached to the base member and positioned adjacent the first wiper blade assembly; a second wiper blade assembly having a second wiper blade attached to the linkage assembly; and means for extending and retracting the linkage assembly.
The linkage assembly has an upper connecting member, a lower connecting member spaced from the upper connecting member, and one or more intermediate connecting members pivotally connected to the upper and lower connecting members. The upper, lower and intermediate connecting members operate like a bellows moving the lower connecting member toward and from the upper connecting member and thereby moving the second wiper blade toward and from the windshield. A cable operated from inside the vehicle extends and retracts the linkage assembly to move the second wiper blade toward and from the windshield.
According to another aspect of the invention, a windshield wiper system comprises a wiper arm; a base member having first and second edge portions and being pivotally attached to the wiper arm; a first wiper blade assembly having a first wiper blade and being attached to the first edge portion of the base member; a second wiper blade assembly having a second wiper blade and being attached to the second edge portion of the base member; a linkage assembly attached to the base member and positioned intermediate the first and second wiper blade assemblies; an intermediate wiper blade assembly having a third wiper blade attached to the linkage assembly; and means for extending and retracting the linkage assembly.
The windshield wiper system has multiple blades for clearing the windshield of rainwater, ice, snow, dust and debris. A pair of outer elastomeric squeegee blades remove rainwater while two pairs of inner blades remove ice, snow, dust and other debris. A rigid blade removes ice while a spongy blade takes care of snow, dust and debris. Each pair of inner blades is movable toward and from the windshield, one at a time, while the outer blades remain fixed. An inner blade moves from a normal position out of contact with the windshield to an extended position where it contacts the windshield lifting the fixed exterior blades away from the windshield. Each movable blade is attached to an accordion linkage mechanism and operated from inside the by the driver vehicle via a cable. There is no longer a need to have only one blade option or the need to stop the vehicle to adapt the wipers to environmental conditions.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings
Referring to
The system 10 includes a base member 18 of metal, plastic or other material that has first and second edge portions and is pivotally attached to wiper arm 16. An exterior or first wiper blade assembly 20 has a first conventional rubber or elastomeric wiper blade 22, and is attached to the first edge portion of base member 18. An exterior or second wiper blade assembly 24 has a second conventional rubber or elastomeric second wiper blade 26, and is attached to the second edge portion of base member 18.
The present invention differs from conventional wiper blade assemblies by providing at least a first, and preferably a second, interior or intermediate wiper blade assembly 28, 30 positioned between exterior wiper blade assemblies 20, 24.
A first linkage assembly 32 is attached to base member 18 and is positioned intermediate the first and second wiper blade assemblies 20, 24. First linkage assembly 32 comprises an upper connecting member 34, a lower connecting member 36, and at least one intermediate connecting member 38 pivotally connected to the upper and lower connecting members 34, 36. The upper, lower and intermediate connecting members form an extension device that operate like an accordion or bellows moving lower connecting member 36 toward and from upper connecting member 34 which is fastened to base member 18.
Intermediate wiper blade assembly 28 has a wiper blade 40 attached to the lower connecting member 36 of the linkage assembly 32. Also attached to the lower connecting member 36 of the linkage assembly 32 is a cable 42. The other end of cable 42 terminates inside the vehicle where it attaches to a knob, panel or other lever for operation. Cable 42 provides a means for extending and retracting linkage assembly 32 and thereby wiper blade 40.
A second linkage assembly 44 is attached to base member 18 and is positioned intermediate the first and second wiper blade assemblies 20, 24 adjacent intermediate wiper blade assembly 28. Linkage assembly 44 comprises an upper connecting member 46, a lower connecting member 48, and at least one intermediate connecting member 50 pivotally connected to the upper and lower connecting members 46, 48. The upper, lower and intermediate connecting members form an extension mechanism that operates like an accordion or bellows moving lower connecting member 48 toward and from upper connecting member 46 which is fastened to base member 18.
Intermediate wiper blade assembly 30 has a wiper blade 52 attached to the lower connecting member 48 of the linkage assembly 44. Also attached to the lower connecting member 48 of the linkage assembly 44 is a cable 54. The other end of cable 54 terminates inside the vehicle where it attaches to a knob, panel or other lever for operation. Cable 54 provides a means for extending and retracting linkage assembly 32 and thereby wiper blade 40.
It can now be appreciated that a windshield wiper system for a machine or a vehicle has been presented that changes wiper blades according to the type of material to be removed from the windshield. Normally, the exterior wiper blades are common squeegee blades constructed of rubber or elastomeric material for moving water. Intermediate wiper blade 40 can be used for snow, dust and mud. Blade 40 may have a deformable surface for contacting the windshield and hugging to it so that it actually removes material rather than simply gliding over the material. A spongy material has the advantage of absorbing moisture that is helpful where there is dust or mud. When a spongy material is used, the cleaning fluid that is normally lost is captured for cleaning. Intermediate blade 52 removes ice. It is formed of a hard plastic material or metal with a pointed working surface so that it is useful for scrapping ice from the windshield and pushing sheets of melting ice off the windshield. Either or both intermediate wiper blades may be used in a wiper assembly, although only one of the blades contacts the windshield at a time.
While the invention has been described with particular reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiments without departing from invention. For example, instead of operating the cables by manually pulling a knob or lever, a cable may be connected to a motor operated by a push button.
As is evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the examples illustrated, and it is therefore contemplated that other modifications and applications will occur to those skilled in the art. For example, a wiper blade for scraping ice may have a sharp edge on a front working surface and a serrated rear working surface like a manual ice scraper. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and scope of the invention.
