Desk chair mat

Abstract

A desk chair mat has a substantially planar upper surface suitable for interaction with a chair support structure, a perimeter defining an outer edge of the mat, a lower surface parallel to the upper surface. An array of generally blunt ended and laterally elongated projections extends downwardly from the lower surface for engagement with a carpet. A decorative pattern is also formed on the lower surface that is visible through the upper surface. Each projection has a smooth end surface spaced below the lower surface by a distance sufficient to penetrate into the carpet pile. The array is generally a regular pattern of the projections that can be arranged at an angle with respect to each nearest neighbor to provide enhanced resistance to lateral movement of the mat with respect to the carpet to protect the decorative pattern from abrasion.

1 . A desk chair mat for interposition between a carpet and a chair, the desk chair mat comprising: a substantially transparent body having a generally planar upper surface suitable for interaction with a chair support structure, a perimeter defining an outer edge of the body, and a lower surface generally parallel to the upper surface, the lower surface including a decorative pattern that is visible through the upper surface and an array of laterally elongated projections having blunt and smooth end surfaces extending downwardly for engagement with any underlying carpet.  
   
   
       2 . The desk chair mat of  claim 1  wherein the smooth end surface of each of the projections is generally parallel to the lower surface.  
   
   
       3 . The desk chair mat of  claim 1  wherein a horizontal cross-sectional aspect ratio of each of the projections is between about 2 and 4.  
   
   
       4 . The desk chair mat of  claim 1  wherein the smooth end surface of each of the projections has an area of at least about 8 mm 2 .  
   
   
       5 . The desk chair mat of  claim 1  wherein the smooth end surface of each of the projections is spaced from the lower surface by about 3 to 10 mm.  
   
   
       6 . The desk chair mat of  claim 1  wherein the projections are arrayed such that each projection is spaced from its nearest neighbor projection by between about 1 and 4 cm.  
   
   
       7 . The desk chair mat of  claim 1  wherein a vertical cross-sectional aspect ratio of the projections is greater than one in a first direction and less than one in a second direction.  
   
   
       8 . The desk chair mat of  claim 1  wherein the array comprises a regular pattern of projections arranged at an angle with respect to each nearest neighbor.  
   
   
       9 . The desk chair mat of  claim 8  wherein the angle is at least 300.  
   
   
       10 . The desk chair mat of  claim 1  wherein some of the projections are connected to each other with ridges that extend from the bottom surface by a distance less than the blunt projections.  
   
   
       11 . The desk chair mat of  claim 1  wherein the decorative pattern extends continuously over the entire lower surface.  
   
   
       12 . The desk chair mat of  claim 1  wherein the decorative pattern extends over only a selected portion of the lower surface.  
   
   
       13 . The desk chair mat of  claim 1  further comprising at least one opening within said perimeter forming a handle for the mat.  
   
   
       14 . A desk chair mat for interposition between a carpet and a chair, the desk chair mat comprising: a semi-rigid sheet of plastic having a substantially planar upper surface suitable for interaction with a chair support structure, a perimeter defining an outer edge of the mat, a lower surface parallel to the upper surface, the lower surface including a decorative pattern that is visible through the upper surface and an array of laterally elongated, blunt ended projections extending downwardly from the lower surface for engagement with any underlying carpet, each projection having a smooth end surface spaced below the lower surface by a distance sufficient to penetrate into the carpet, the array being a regular pattern of the blunt projections arranged at an angle with respect to each nearest neighbor to provide resistance to any lateral movement of the mat with respect to the carpet.  
   
   
       15 . A method of manufacturing a desk chair mat for interposition between a carpet and a desk chair, the method comprising the steps of: 
 providing a first roll having a surface including an array of cavities,    coupling the first roll to a second roll to define a nip of selected dimension,    extruding a stream of plastic into the nip under conditions ensuring that the array of cavities will be generally filled by the plastic to form a decorative pattern that is visible through the upper surface and an array of laterally extending, blunt ended projections on a first surface of a continuous web of plastic,    defining a perimeter of a mat surrounding the first and second areas of the continuous web, and    separating the mat within the perimeter from the continuous web.    
   
   
       16 . The method of  claim 15  further comprising a step of creating a graphic image on the surface of the first roll.  
   
   
       17 . The method of  claim 15  further comprising a step of creating a graphic image on the mat by printing the image on a surface of the continuous web.  
   
   
       18 . The method of  claim 15  further comprising the steps of creating a graphic image on a separately formed web and bonding the separately formed image to a surface of the continuous web.  
   
   
       19 . The method of  claim 15  further comprising the step of shaping the interior of the cavities to have a smooth truncated end surface capable of molding the smooth blunt ended projections.  
   
   
       20 . A desk chair mat for interposition between a carpet and a chair, the desk chair mat comprising: a semi-rigid sheet of plastic having a substantially planar upper surface suitable for interaction with a chair support structure, a perimeter defining an outer edge of the mat, a lower surface parallel to the upper surface, the lower surface including a three-dimension decorative pattern that is visible through the upper surface, the decorative pattern including sufficient vertical relief to comprise an array of laterally elongated, blunt ended projections extending downwardly from the lower surface for engagement with any underlying carpet.