Patent Publication Number: US-2012025052-A1

Title: Aesthetic coasters

Description:
BACKGROUND AND SUMMARY 
     For many years aesthetic coasters for drink glasses (which coasters can also perform other conventional functions, such as paper weights, plant pot bases, art objects, or the like, which conventional functions are inherently incorporated within the term “coasters”) have been made of high quality, expensive metal such as brass or bronze. Because of the very high cost of such coasters, prior art techniques have been used to provide substantially the same aesthetic effect while making the coasters cheaper to produce. For example, a prior art coaster has been made from steel discs with brass sheet wrapped around a disc and bent at the bottom to hold the brass onto the steel disc, with the disc and bent brass bottom covered with felt. As a still less expensive prior art version, aluminum sheet has been used in place of the brass sheet, and a lacquer coating provided on the aluminum to provide a more aesthetic color (such as brass or silver). 
     According to the invention a coaster is provided that is just as functional, if not more functional, than the prior art coasters described that is even less expensive, yet still has substantially the same look as a brass or like high quality aesthetic coaster. 
     According to the invention, the coaster body is made of plastic having an aesthetic top surface (and side wall) and a recessed bottom. For some coasters, where optimum aesthetics is not required, the body may be made simply by injection molding using a highly polished mold cavity, and a glossy grade of plastic (e.g. black ABS). However most desirably, in order to substantially accurately simulate a high quality metal coaster, after the plastic coaster body is injection molded it is subjected to vacuum coating (sometimes also known as vacuum deposition, metallizing, or plating). In that process, aluminum (or other metal) is vaporized in a vacuum chamber so that the aluminum condenses to form a micro millimeter coating on the top surface of the plastic coaster body positioned within the vacuum chamber, and then the top surface of the plastic coaster body is coated with a low temperature catalytic lacquer. While under some circumstances the lacquer may be clear, most desirably the lacquer produces an imitation chrome, silver, brass, copper, bronze, or gold color. 
     While vacuum coating is definitely preferred, other conventional techniques capable of applying a micro layer of Al or other metal may alternatively be used. 
     While plastic per se has been used in drink coasters (e.g. see U.S. Pat. No. 5,150,869 and US Published Patent Application 2007/0034766), it has not believed known used as the visible part of an aesthetic coaster, as according to the invention. 
     According to one aspect of the invention, there is provided a method of making a coaster comprising: a) making a plastic coaster body having an aesthetic top surface and a recessed bottom surface; b) inserting an insert having a density significantly greater than the density of the plastic coaster body into the recess in the recessed bottom surface of the coaster body; c) substantially permanently adhering the insert within the recess; and d) providing the insert and recess with a covering which will not scratch furniture surfaces or the like. 
     In the method, b) may be practiced using a mild steel insert, and b) may be further practiced so that the coaster produced has about the same weight and feel as a similar sized coaster formed primarily or substantially completely of brass or bronze. Typically, c) is practiced using adhesive, such as by using double sided adhesive tape around the periphery of the insert, or using an adhesive between a large substantially flat top surface of the insert and a large substantially flat bottom surface of the body defining the recess. A felt or cork sheet-like covering may be used to practice d). 
     In one aspect of the invention, a) is practiced by injection molding using a highly polished mold cavity, and a glossy grade of ABS plastic (e.g. black). More universally, a) is practiced by a1) injection molding the plastic coaster body; then a2) vaporizing aluminum in a vacuum chamber so that the aluminum condenses to form a micro millimeter coating on at least the top surface of the plastic coaster body positioned within the vacuum chamber, or otherwise forming a micro layer of aluminum or other metal on at least the top surface of the plastic coaster body a3) then coating at least the top surface of the plastic coaster body with a low temperature catalytic lacquer. Typically, a3) is practiced with a lacquer that produces an imitation chrome, silver, brass, platinum, copper, bronze, or gold color. 
     According to another aspect of the invention, there is provided an aesthetic coaster comprising: a plastic coaster body having a substantially flat top surface with an annular raised periphery, and a bottom with a recess therein, at least the top surface of said plastic coaster body coated with a micro millimeter layer of aluminum, the aluminum covered with a lacquer with an imitation metal color; an insert substantially permanently held in said recess, said insert of a material having a density significantly greater than that of said coaster body; and a covering which will not scratch furniture surfaces covering said insert and recess. 
     The insert may be made of steel or the like, and desirably the coaster has a weight and feel substantially the same as if the coaster were formed substantially entirely of brass or bronze. The insert may be held in said recess by an adhesive acting between a substantially flat top surface of the insert and a substantially flat bottom surface of the coaster body within the recess. The covering may sheet felt held in place with pressure sensitive adhesive. Desirably, the imitation metal color is selected from silver, brass, chrome, platinum, copper, bronze, and gold. 
     The invention also relates to a coaster made by practicing any of the methods described above. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a box diagram illustrating an exemplary method according to the present invention; 
         FIG. 2  is a side exploded view, partly in cross section and partly in elevation, of a plastic coaster body and steel insert during assembly of a coaster according to the invention; 
         FIG. 3  is a view like that of  FIG. 2  with the insert and body affixed together; 
         FIG. 4  is a view like that of  FIGS. 2 and 3  of the completed coaster with felt covering on the bottom; 
         FIG. 5  is a top perspective view of exemplary round coasters according to the invention; and 
         FIG. 6  is a top plan view of a polygonal (square) coaster according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF DRAWINGS 
     As seen in  FIG. 1 , in an exemplary method according to the invention, the coaster body is injection molded at  10  from any suitable high quality plastic, such as ABS. In the preferred method, forming the most aesthetic coaster, the plastic body is placed in a vacuum chamber and vacuum coated at  11  with aluminum or other suitable metal. That is, at  11  aluminum is vaporized in a vacuum chamber so that the aluminum condenses to form a micro millimeter coating on at least the top surface of the plastic coaster body positioned within the vacuum chamber. Then, at  12 , at least the top surface (and side wall) of the plastic coaster body is coated with a low temperature catalytic lacquer, desirably one imparting an imitation expensive-looking metal color, such as with a lacquer that produces an imitation chrome, silver, brass, copper, platinum, bronze, or gold color. 
     At  13 , an adhesive is applied to a mild steel, or like relatively inexpensive dense material (e.g. iron or ceramic) insert, and/or to the interior of the plastic coaster body. The adhesive may be in the form of an adhesive coat between large substantially flat insert top and plastic body bottom surfaces, or a double faced tape around the periphery of the insert. The adhesive may be pressure sensitive, hot melt, or a type that cures by application of heat or some other conventional external stimulus. 
     After adhesive application at  13 , at  14  the steel insert is inserted into the bottom recess of the plastic body with the adhesive holding the insert substantially permanently in place. Then, as is conventional, at  15  the insert (and recess) are covered with a material that will not scratch or mar furniture, preferably a felt sheet covering that bonds to the insert and periphery of the plastic body with an adhesive. Alternatively cork, leather, rubber, vinyl, or the like, either in sheet form or in the form of spaced feet, may be used in place of or in addition to felt. 
     Typically the plastic body has a raised annular periphery, and in many circumstances, as indicated at  16 , and as is conventional per se, a digital color insert, hot stamped leather insert, or embedded leather medallion, is optionally provided on the top surface of the plastic coaster body within the area defined by the raised annular periphery. Also if desired a design could be formed on the top surface of the plastic coaster body during injection molding, or by an etching process or the like after molding and before procedures  11  and  12 . 
     For a somewhat less desirable—though still aesthetic—version of the method of  FIG. 1 , the molding at  10  is done—as indicated at  17 —with a highly polished mold and glossy plastic, such as black ABS. Then the procedures  11  and  12  are not necessary. 
       FIG. 2  shows, in cross-section, an exemplary plastic coaster body  20  according to the invention. The body has a substantially flat top surface  21 , and a substantially flat bottom surface  22  at the bottom of a bottom recess  23 . The bottom recess  23  is defined by the substantially annular side wall  24 , which has a dimension D substantially the same as, or slightly less or greater than, the thickness of the insert  25 . Also, preferably the coaster body  20  has a raised annular peripheral lip  26  defining the edge of the top surface  21 , and the insert  25  has a substantially flat top surface  27 . 
     The insert  25  typically has a thickness of about 2.5-5 mm (e.g. about 3.55 mm) and is in the form of a disc when the completed coaster (e.g. see  31  in  FIGS. 4 &amp; 5 ) is circular. While a number of different relatively inexpensive materials, such as iron and dense ceramic, may be used, preferably the insert  25  is of mild steel with substantially no burrs or other significant surface imperfections. Whatever the insert  25  material, it has a sufficient density and thickness (ultimately weight) so as to make the completed coaster ( 31  in  FIGS. 4 &amp; 5 ) feel like it is made of the material that the plastic body top surface simulates (e.g. brass, bronze, silver, etc.). Also, since the insert  25  takes up substantially the entire recess  23 , the center of gravity and uniformity of feel of the completed coaster ( 31 ) is such as to also simulate a coaster primarily or substantially entirely of high quality material (such as brass). 
       FIG. 3  shows the insert  25  held substantially permanently in place within the recess  23  by an adhesive (shown only at spot  30  in  FIGS. 2 &amp; 3  but desirably almost completely coating one or both of the surfaces  27  and  22 ). Instead of an adhesive—which may be hot melt, pressure sensitive, heat or other external stimuli activated, etc.—between the surfaces  22 ,  27 , a conventional double faced adhesive tape may be provided between the periphery of the insert  25  and interior of the annular side wall  24 . 
     Another way that adhesive could be used to attach the components  20 ,  25 , together would be to use a disc of double sided dry mount adhesive. The disc could be made as a die cut from wide strip double sided tape with suitable wax or polyethylene coated release papers as is established practice. A die cut disc of self adhesive dry mount the same size and shape as the insert  25  could pre-applied to the insert  25 , and then the remaining protective backing removed immediately prior to insertion into the recess  23 . 
     Another way of adhesively securing the components  20 ,  25 , would be to extrude a generous bead of a silicone sealant or the like into the internal profile ‘V’ recess  23  of the coaster body  20 , and then insert the steel plate  25 . The result would be that the silicone would then extrude between the plate and molding flat surfaces and also in the space between the insert edge and the inside wall of the molding. Any surplus of adhesive could easily be wiped clean. 
     Still further, under some circumstances one could heat or cold swage the plastic body  20 , such as at the sidewall  24 , thereby deforming the plastic to trap the insert  25 , obviating the need for adhesive. A felt base (as described below) could be suitably arranged to provide an adequately performing base. Still further, the inside of the side wall  24  could be molded with clips so that the insert  25  clips into place without adhesive or swaging. 
       FIG. 4  shows a side view of a completed coaster  31  having a covering  28  over the insert  25  and recess  23 , preferably including the side wall  24 , which covering  28  will not harm furniture or other surfaces on which the coaster  31  might be placed. In  FIG. 4  the plastic coaster body and covering  28  are shown in cross-section, and the insert  25  in elevation. The covering  28  may be any conventional material, such as felt about 1 mm thick secured by conventional pressure sensitive adhesive to the bottom surface  29  of the insert  25  as well as the termination of the annular side wall  24 . Other conventional materials that may be used for the covering  28  include, without limitation, cork, leather, vinyl, and rubber. The term “covering” is used herein generically, and includes a complete sheet-like covering as illustrated in  FIG. 4 , or spaced feet, as long as the covering  28  properly supports the coaster  21  to function properly as a coaster and so that it does not harm surfaces on which it is placed. 
     While the completed coaster  31  may have a wide variety of dimensions, typically it has a diameter of about 3.5-4 inches. 
       FIG. 5  provides a schematic perspective view of three circular coasters  31  according to the invention. In each case within the area defined by the raised annular periphery  26  of the coaster plastic body  20  there is provided (in a manner conventional per se, as schematically illustrated at  17  in  FIG. 1 ) a custom or standard digital color insert, hot stamped leather insert, or embedded leather medallion,  33 . 
     While normally the coasters  31  are circular, they may be of a wide variety of shapes, such as ovals, clover leafs, hearts, or polygons. One polygonal form (square as illustrated) of a coaster  34  is illustrated schematically in  FIG. 6 . Whatever the shape, the insert ( 25 ) will typically have substantially the same shape as the plastic body ( 20 ), for example square in the case of the  FIG. 6  coaster  34 . 
     While the invention has been described with respect to preferred embodiments, it is to be understood that the invention is to be interpreted to cover all reasonable equivalents, and the invention is to be accorded the broadest interpretation possible consistent with the prior art.