Patent Publication Number: US-8973206-B1

Title: Trowel with depth adjustment

Description:
FIELD OF THE INVENTION 
     This invention relates to the installation of tile on mortar beds and a device for laying a bed of mortar evenly at a desired height to ensure that each tile laid on the mortar bed is the exact same height, thereby creating a level field of tiles. 
     BACKGROUND OF THE INVENTION 
     Thick set mortar beds used for installing tile, also referred to as thick-bed installations, are based on the traditional method of packing a mortar bed over a surface or substrate before installing tile. The tile is adhered to the mortar bed either while the mortar bed is still wet or after the mortar bed has cured using a mastic. The terms thick-bed installation, mortar bed installation, and thick-set installation are synonymous. 
     Mortar beds allow an installer of tile to level out unevenness in the substrate, thereby creating an ideal surface to which the tile can be bonded. 
     This is especially important when laying uneven tiles. Natural stone tiles, such as slate, marble, travetrertine, limestone and so forth, often have unfinished or unpolished lower surfaces that when placed on a thin set of mastic have a tendency of coming into contact with the uneven areas of substrate and not laying level. This causes an uneven unprofessional installation job. In addition, this can cause the tiles to have raised edges that are tripping hazards. Thus, thick-bed installation is ideal for natural stone tiles. 
     However, a common problem with the installation of mortar beds is the time and work involved with laying and troweling the mortar. The skill required to lay an even bed of mortar using a conventional trowel is a major factor in the cost and time required to ensure the mortar bed is perfectly level and thus the tiles are laid evenly. 
     Therefore, a need exists for a trowel having depth adjustment guides that level a mortar bed to an even desired height over an uneven substrate. 
     The relevant prior art includes the following references: 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Pat. No. 
                 Inventor 
                 Issue/Publication Date 
               
               
                   
                   
               
             
            
               
                   
                 (U.S. Patent  
                   
                   
               
               
                   
                 References) 
                   
                   
               
               
                   
                 3,758,945 
                 Finnegan, Jr. 
                 Sep. 18, 1973 
               
               
                   
                 4,901,801 
                 Popivalo 
                 Feb. 20, 1990 
               
               
                   
                 5,231,729 
                 Rose 
                 Aug. 3, 1993 
               
               
                   
                 7,028,366 
                 Brozoska 
                 Apr. 18, 2006 
               
               
                   
                 2009/0217476 
                 Hurley et al. 
                 Sep. 3, 2009 
               
               
                   
                 7,757,335 
                 Servidio 
                 Jul. 20, 2010 
               
               
                   
                 8,256,809 
                 Coutu 
                 Sep. 4, 2012 
               
               
                   
                 (Foreign Patent  
                   
                   
               
               
                   
                 References) 
                   
                   
               
               
                   
                 GB2,259,938 
                 Phillips 
                 Mar. 31, 1993 
               
               
                   
                   
               
            
           
         
       
     
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a trowel having depth adjustment guides that level a mortar bed to an even desired height over an uneven substrate. 
     The present invention fulfills the above and other objects by providing a trowel having a rounded plate slidably attached to a flat plate. The flat plate is preferably attached to an angled handle. Curved prongs extend from the flat plate through apertures located on the rounded plate. The prongs are used to obtain a desired depth of a mortar bed as the rounded plate is used to smooth out the mortar bed. An upper surface of the rounded plate may be used as a flat trowel or scoop when the trowel is turned over. 
     An added feature of the trowel is that the handle of the device may be extendable and/or interchangeable. 
     The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description, reference will be made to the attached drawings in which: 
         FIG. 1  is a side view of a trowel of the present invention in use with a plurality of prongs pressed against a substrate to obtain a desired depth as the trowel is being pulled toward a user; 
         FIG. 2  is a side view of a trowel of the present invention flipped upside down; 
         FIG. 3  is a top view of a trowel of the present invention; and 
         FIG. 4  is a bottom view of a trowel of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of describing the preferred embodiment, the terminology used in reference to the numbered components in the drawings is as follows:
           1 . trowel, generally     2 . prong     3 . substrate     4 . user     5 . flat plate     6 . rounded plate     7 . aperture     8 . lower surface of rounded plate     9 . mortar bed     10 . handle     11 . upper surface of rounded plate     12 . sliding means     13 . locking means     14 . slot     15 . nut     16 . bolt       

     With reference to  FIG. 1 , a side view of a trowel  1  of the present invention in use with a plurality of prongs  2  pressed against a substrate  3  as the trowel  1  is being pulled toward a user  4  is illustrated. The trowel  1  comprises a plurality of prongs  2  extending from a flat plate  5  slideably attached to a rounded plate. The plurality of prongs  2  extend through corresponding apertures  7  located in the rounded plate  6  (as illustrated in  FIGS. 3 and 4 ). The plurality of prongs  2  are preferably curved so that they are substantially parallel to the rounded plate  6 . This allows the plurality of prongs  2  to maintain a proper depth as a lower surface  8  of the rounded plate  6  smoothes the surface of the mortar bed  9  as the trowel  1  is pulled through the mortar bed  9  using a handle  10  located on the trowel  1 . 
     With reference to  FIG. 2 , a side view of a trowel  1  of the present invention flipped upside down is illustrated. By turning the trowel  1  over an upper surface  11  of the rounded plate  6  may be used as a scraper or scoop. 
     With reference to  FIGS. 3 and 4 , a top view and a bottom view, respectively, of a trowel  1  of the present invention are illustrated. The flat plate  5  is slideably attached to the rounded plate  6  by a sliding means  12  and a locking means  13 . As illustrated here, the sliding means  12  is at least two slots  14  located on the rounded plate  6  and/or the flat plate  5  and at least one locking means  13 , such as nuts  15  and bolts  16  that fit though the slots  14 . Other sliding means  12  and locking means  13  may include combinations of guides, clamps and so forth. The slideability of the flat plate  5  and rounded plate  6  allow a user to extend the prongs  2  through the apertures  7  in the rounded plate  6  depending on the desired height of the bed of mortar  9  being placed over the substrate  3 , as illustrated in  FIG. 1 . 
     It is to be understood that while a preferred embodiment of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings.