Abstract:
A method of constructing and making a squeegee blade includes forming a mounting plate with support members attached to a surface of the mounting plate. Forming a flexible blade and securing the flexible blade to the surface of the mounting plate with the support members embedded so that the flexible blade is supported by the support members against compression toward the mounting plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     This is an utility application, which claims priority to U.S. Provisional Application No. 60/467,438 filed on May 1, 2003. 
    
    
     BACKGROUND OF INVENTION  
     1. Field of the Invention 
     The invention relates generally to squeegee blades for use on construction equipment. 
     2. Background Art 
     Rubber cutting edge blades have been made with a rubber portion adhered to a mounting plate that is bolted to the existing blade of a front end loader, dozer or other construction equipment. These blades are typically bolted by the mounting plate to the bucket of a front end loader, a shovel blade, caterpillar blade, bull dozer blade or other material moving blade of and industrial tractor, construction equipment or other heavy equipment. Such attached rubber edged blades are particularly useful in warehouses and other floored industrial environments to scrape or squeegee loose materials or liquid from the floor. When in use, the heavy equipment can place large downward forces on the rubber of the blade with hydraulic blade actuation while moving the blade and causing it to scrape along the floor or ground surface with the powerful motivating force of the heavy equipment. Rapid abrasion and wear have been noted. 
     SUMMARY OF INVENTION  
     One aspect of the invention provides a squeegee blade that includes a relatively rigid mounting surface, at least one relatively rigid support secured to the mounting surface, and a relatively flexible blade secured to the mounting surface and positioned adjacent to the at least one relatively rigid support, so that the relatively rigid support acts to support the flexible blade against compression toward the relatively rigid mounting surface. 
     Another aspect of the invention provides a mounting mechanism for a squeegee blade including an elongated slot having a narrow channel with a first end in one direction and a second end in an opposite direction, the narrow channels sized for receiving the shaft of fasteners therethrough and for holding against the head of the fasteners and having a wide portion positioned toward the first end of the narrow channel and sized for receiving the head of the fasteners thererthrough and at least one keyhole shaped hole having a short narrow channel, the short narrow channel extending a short distance along the mounting plate, and having a wide portion in the one direction and the short narrow channel portion at another end portion, the narrow channels sized for receiving the shaft of the fasteners therethrough and for holding against the head of the fasteners and the wide portion sized for receiving the head of the fasteners thererthrough. 
     Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS  
         FIG. 1  is a perspective view of a squeegee blade shown attached to a front end loader. 
         FIG. 2  is a perspective view of a prior art squeegee blade. 
         FIG. 3  is a top perspective view of a prior art mounting plate to which rubber is adhered to form the prior art squeegee blade of  FIG. 2 . 
         FIG. 4  is a bottom perspective view of a prior art mounting plate of  FIG. 3 . 
         FIG. 5  is a perspective view of a squeegee blade according to an embodiment of the invention. 
         FIG. 6  is a top perspective view of a mounting plate to which rubber is molded to form the squeegee blade of  FIG. 5 . 
         FIG. 7  is a bottom perspective view of the mounting plate of  FIG. 6 . 
         FIG. 8  is a perspective view of a squeegee blade according to another embodiment of an example aspect of the present invention. 
         FIG. 9  is a top perspective view of a mounting plate to which rubber is molded to form the squeegee blade of  FIG. 5  according to an example aspect of the invention. 
         FIG. 10  is a bottom perspective view of the mounting plate of  FIG. 9   
         FIG. 11  is a perspective view of a squeegee blade according to another embodiment of example aspect of the present invention. 
         FIG. 12  is a top perspective view of a mounting plate to which rubber is molded to form the squeegee blade of  FIG. 11  according to example aspect of the invention. 
         FIG. 13  is a bottom perspective view of the mounting plate of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION  
     Referring to  FIG. 1 , a piece of heavy equipment  10  is shown having a bucket  12  with a lower blade  14  to which a blade  16  with a rubber cutting edge is secured with fasteners through a plurality of attachment holes  18  in the lower blade  14  of the bucket  12 . The rubber blade  16  comprises a rubber portion  20  and a mounting plate  22 . It has been discovered that in use the rubber portion  20  can be placed under significant pressure and strain. The compressed rubber portion  20  can abrade quickly, particularly when it is moved under pressure across a concrete floor, an asphalt roadway, a paved surface or another abrasive ground surface. Under such conditions, and when the rubber is strained, the rubber portion  20  of the blade is more likely to tear and rupture, so that the adverse abrasive effect of movement against a floor  24  or against another surface, is accelerated. 
     Thus, it has been discovered that under significant pressure, the compressed rubber of a rubber edged blade is abraded quickly. When the rubber is compressed and strained it is more likely to tear and rupture, thereby accelerating the adverse effect of the abrasion. The present invention provides a squeegee blade that has a rubber portion with embedded support members that act to limit the compressive forces and the strain placed on the rubber. Reducing the compression of the rubber portion reduces the effect of abrasion and improves the useful life while maintaining the function of rubber to floor contact, thereby providing a desirable squeegee blade. 
     Referring to  FIGS. 2 ,  3  and  4  a typical construction of a prior art rubber edged blade  26  is shown. 
       FIG. 2  shows a prior blade  26  that typically includes a metal mounting plate  28  and a rubber portion  30 . The mounting plate  28  has a plurality of mounting holes  32  formed therein corresponding to the location of attachment holes  18  formed in the lower blade  14  of a bucket  12  attached to heavy construction equipment, such as a front end loader or similar. The locations of the mounting holes  32  must match closely to the locations of the attachment holes  18  for a particular blade  14  or piece of equipment  10 . The rubber portion  30  is adhered to the mounting plate  28 . The rubber portion  30  has bores  38  formed through the rubber at each mounting hole, to permit the fasteners  34 , such a bolts  34 , to be inserted and secure to the mounting plate  28 , for example with threaded holes  18  in the blade  14  or with nuts  36  on the opposite side of the blade. 
       FIG. 3  shows a surface  40  of prior mounting plate  28  that abuts against the bucket blade  14 . 
       FIG. 4  shows the prior bonding surface  42  to which the rubber portion  30  is adhered. The mounting holes may be provided with chamfers  44  to permit the bolts to firmly seat against the mounting plate. 
     Referring to  FIGS. 6 ,  7  and  8 , an embodiment of a squeegee blade  46  of the present invention is shown having a mounting plate  48  and a rubber portion  50  adhered to the mounting plate  48 . In this embodiment a plurality of mounting holes  52  are formed on the mounting plate  48 . To facilitate ease of assembly and alignment of the squeegee blade  46  on existing attachment holes  18  in the blade  14 , the mounting holes  52  are formed as keyhole shaped openings, including a narrow slot or channel portion  55  sized for receiving a shaft of a fastener and for engaging a head of the fastener. At one end of the channel portion a wide portion is formed sized for receiving therethrough the head of the fastener  34  therethrough. The heads of bolts or fasteners  34  may be inserted through a large open portion  53  of the keyhole shaped mounting holes  52 . With all of the bolts  34  in place, the heads of the bolts  34  may be slid along a narrow channel portion  55  into alignment with the existing holes  18 . The aligned bolts are engaged in the holes  18 , for example threaded into the holes  18  or secured with a nut  36 , and the squeegee blade  46  is secured by tightening the bolts. Potential difficulties from minor mismatching of the locations of the mounting holes  52  with existing attachment holes  18  are thus reduced or avoided, thereby accommodating a wider variety of types of existing buckets  12 , blades  14  and equipment  10 . Allowing a larger range of tolerances also reduces the cost of manufacture. 
     In one alternative embodiment at least one of the mounting holes  52  is formed with a keyhole shape that is reversed in direction, as by rotating it 180 degrees, from the other mounting holes  52 . This facilitates keeping the squeegee blade  46  held onto the equipment  10 , even when minor loosening of the bolts might occur during use. An example of a reverse direction keyhole shaped mounting hole is shown at reference number  54 . No matter which lateral direction the squeegee blade  46  might slip along the narrow portions  55  of the keyhole openings  52 , the head of the bolt  34  engaged in the reverse direction key hole  54  will be prevented the other bolts  34  from reaching the wide opening portions  53 . In this embodiment, when a squeegee blade  46  slips due to partially loosened bolts  34 , the squeegee blade  46  can be re-tightened before it falls completely free from the equipment  10 . 
       FIG. 6  shows the mounting plate  48 , viewed from the top, before the rubber portion  50  is molded or otherwise adhered to it. In this embodiment, at least one support member, such as at least one runner  56  is attached to mounting plate  48 . In the embodiment depicted, a plurality of runners  56  are attached to the mounting plate  48 . The rubber portion  50  is formed interposed around the runners  56  and adhered to the mounting plate  48  and to the runners  56 . In an example embodiment, the at least one runner  56  is formed of metal. In one embodiment, the mounting plate  48  is made of metal, such as steel, and each runner  56  is formed of a plate or a bar of a similar type of metal so that it is conveniently secured to the mounting plate  48  by welding. The runners  56  have a height that is initially about the same or slightly shorter than the desired depth from the top to the bottom of the rubber portion  50 . For example, a plurality of relatively rigid runners  56  formed of metal plates may be secured at right angles downward from the mounting plate and extending parallel to one another in the forward and reverse direction of the construction equipment. It has been found by applicants that several of such runners  56  formed of metal plates each about 1 inch to 2 inches (about 2.5 to 5 cm) thick (see thickness “t” in  FIG. 7 ) and secured at right angles to the mounting plate  48  provide good support against downward forces and allow for sliding without damage in forward and reverse directions of the construction equipment. The rubber portion  50  is usefully molded and adhered, as by laying raw rubber between and around the runners with or without adhesive agents at the interfaces and subjecting the entire squeegee blade to heat and pressure in a vulcanization process to cure the raw rubber. In one embodiment the rubber portion  50  is between the runners and also sufficiently deep (top to bottom) to also encapsulate the runners within the cured rubber. 
     When the squeegee blade  46  is in use, the rubber portion  50  will compress up against the bottom surfaces  58  of the runners  56  and then the runners  56  will support the pressure of the blade. Even when the rubber portion  50  wears away to the surfaces  58  of the runners  56 , the rubber portion  50  will continue to make contact, or to be in sufficiently close proximity, with the floor or ground surface between the runners to provide a desired “squeegee” function for many types of materials. Note that the term squeegee as used herein is not limited to squeegee of liquid materials, but also includes granular or nodular materials. After the rubber is worn to the runners  56 , relatively rigid material of the runners  56  generally wears only slowly, even when used on very abrasive surfaces. Support from the runners prevents large strains from being placed on the rubber portion  50  that remains between the runners  56 . With the strain on the rubber reduced, the rate of wearing, tearing, abrasion, and other deterioration is reduced. Thus, the support from the runners  56  reduces the rate of wear of the rubber portion  50 . 
     By reducing the rate of wear and abrasion using embedded runners  56  according the invention, rubber edged blades and squeegee blades can be made with less depth (top to bottom) without reducing their useful life. Such less deep blades can be beneficial for scraping ground and floor surfaces, and picking up materials, such a nodular and fine granular materials. 
       FIG. 7  shows the runners  56  from the bottom or the adhering side of the mounting plate  48 . The runners  56  have a sufficient thickness “t” so that the pressure of the squeegee blade against the ground or floor at any one location along the squeegee blade  46  will not unduly gouge or scratch into a typical concrete floor or paved surface. For example, runners  56  having a thickness of 1″ to 2″ (2.5 to 5 cm) have been found to work for this purpose. Also, included is a bolt head guard, such as a bolt channel  60 , which prevents the molded rubber from interfering with the heads of bolts  34  when securing the squeegee blade  46  to the existing blade  14 . The runners  56 , as described can be formed of metal or other relatively rigid, hard, abrasion resistant, incompressible material, that provides a squeegee blade with runners that act to limit the compressive forces and the strain placed on the rubber of the squeegee blade. By reducing the effect of abrasion, an extended useful life of the squeegee blade is obtained. 
     In  FIGS. 8 ,  9  and  10  an alternative embodiment of a squeegee blade is shown having an elongated mounting slot  62  having at least one wide opening  66  and an elongated slot portion  68 . In one example embodiment as shown, there is also at least one reverse direction keyhole opening  64  separated from the elongated slot  62  by a portion of blade  14 . At least one of the bolts  34  is inserted into the at least one key hole opening  64  and the bolt is aligned with one of the attachment holes  18  in an existing blade  14 . The heads of a plurality of other bolts  34  are inserted into the wide portion  66  of mounting slot  62  and the bolts  34  are moved along a narrow elongated slot  68  to positions as required for alignment with and mounting to several remaining attachment holes  18  in an existing blade  14 . The wide opening  66  of the elongated slot  62  is therefore positioned in an opposed direction from an open portion  70  of keyhole opening  64 . As long as the bolts do not disengage from the nuts or from the threaded holes in the existing blade  14 , the squeegee blade  46  remains attached to the equipment. Thus, the rubber edge blade  46  is prevented from sliding off the heads of the bolts  34  even when the bolts  34  might work loose. Thus, the slotted mounting arrangement depicted can be used to accommodate a wide variety of exiting attachment holes  18  without the need to custom make each rubber edged blade. 
     In  FIGS. 11 ,  12 , and  13  the elongated mounting slot and keyhole opening arrangement of  FIGS. 8 ,  9  and  10  is applied to and can be combined with a squeegee blade having embedded metal runners according to other aspects of the present invention. 
     VARIATIONS AND EQUIVALENTS 
     It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, terms with directional connotations such as top, bottom, upper, lower, outer, inner, side and end are used in context for purposes of relative positions and the device need not be limited to absolute directions in order to fall within the scope of the invention described and claimed. While various features and embodiments are described in certain combinations and sub-combinations, selected features from one embodiment may be combined with features of other embodiments without departing from certain aspects of the invention. 
     Although only a few example embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many other modifications and variations are possible in these and other embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as claimed and for which applicants may be entitled to patent protection.