Abstract:
A furniture cap or glide that is secured to a leg of an article of furniture, wherein the cap or glide defines an axis and has a lower surface and a sidewall spaced from the axis. The lower surface has a plurality of inner protrusions, a plurality of outer protrusions, and a series of connectors extending therefrom. The outer protrusions extend from the lower surface a first predetermined distance. The inner protrusions extend from the lower surface a second predetermined distance, which is smaller than the first predetermined distance. The connectors extend between and interconnect the some of the inner and outer protrusions, and extend from the lower surface a third predetermined distance. Initially, the outer protrusions engage the floor surface but, as the cap wears from use, the inner and outer protrusions simultaneously engage the floor surface, and thereby provide objective visual indication that the cap has worn a first amount. Upon further wear, the protrusions and the connectors engage and slide across the floor surface, and thereby indicate that a second amount of wear has occurred.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to furniture, and more particularly to furniture glides and caps. 
     2. Description of Related Art 
     Moving furniture across a floor surface can be problematic in that the furniture legs contacting the floor surface can scratch or gouge the floor surface during movement. Dirt and debris on the floor surface can build up in front of a moving furniture leg so as to increase the difficulty of the movement. 
     Devices, such as caps, glides, rollers and pads, are used to decrease the difficulty of moving furniture across a floor. The devices protect the floor from scratches or gouges by the moving floor legs. The devices also reduce friction between the furniture leg and the floor surface to facilitate moving. Unfortunately, dirt and debris on the floor surface can still be a problem. Essentially, the dirt and debris may become trapped beneath the glide or cap&#39;s lower surface and then be ground into the floor when the furniture is moved. 
     Attempts to address the problem of dirt and debris on the floor surface include U.S. Pat. No. 6,324,725, which discloses glides having “stipples,” which are hemispherical, dot-like structures on the bottom of the glide. Unfortunately, even with the stipples of the &#39;725 patent, dirt and debris on the floor may still collect in the space between the stipples as the furniture is moved across the floor surface. Also, as the stipples inevitably wear down the collection space diminishes, further capturing dirt and reducing the effectiveness of the glide. The arrangement of the stipples does not provide direct paths for the dirt and debris to travel beneath the moving glide. Accordingly, dirt and debris can build up in front of each stipple in a manner similar to the build-up of dirt and debris in front of a glide without stipples as the furniture is slid across a floor. 
     Further, in the glides and caps known in the art there is no indication of wear, making it difficult to objectively determine when replacement of the cap or glide is warranted. Therefore, in the prior art direct observation and subjective judgment is relied on to determine whether a cap or glide should be replaced. 
     Therefore, there is a need in the art for a cap or glide that facilitates moving furniture across a floor surface. There further exists a need in the art for a cap or glide that directs dirt and debris thereunder as the furniture is moved across the floor surface. There also exists a need for a cap or glide that includes a structure to permit objective determination of the degree of wear of the cap or glide. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward a cap or glide that facilitates moving furniture across a floor surface, and directs dirt and debris under the cap or glide as the furniture is moved across the floor surface. The present invention is further directed toward a cap or glide that permits objective determination of the degree of wear of the cap or glide. 
     In accordance with the present invention, a cap is cup-shaped and defines an axis, and has an upper surface, a lower surface, a sidewall, and a plurality of downwardly extending protrusions. The cap upper surface defines a receptacle that receives a bottom of a furniture leg. The plurality of protrusions extend or project downwardly from the cap lower surface, the protrusions including a plurality of outer protrusions and plurality of inner protrusions. The outer protrusions extend from the lower surface a predetermined first distance; the inner protrusions extend from the lower surface a predetermined second distance. The second distance is smaller than the first distance. 
     In further accordance with the invention, a furniture glide is provided. The glide is adapted to be secured to a bottom end of a furniture leg. The glide has a lower surface from which a plurality of protrusions extend. The protrusions include a plurality of outer protrusion and a plurality of inner protrusions. The outer protrusions extend from the lower surface a predetermined first distance; the inner protrusions extend from the lower surface a predetermined second distance. The second distance is smaller than the first distance. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and further features of the invention will be apparent with reference to the following description and drawings, wherein: 
     FIG. 1 is a perspective view of a cap in accordance with the present invention; 
     FIG. 2 is a bottom plan view of the cap shown in FIG. 1; 
     FIG. 3 is a top plan view of the cap shown in FIG. 1; 
     FIG. 4 is a side elevational view of the cap shown in FIG. 1; 
     FIG. 5 is a cross-sectional view of the cap of FIGS. 1-4 taken along the line  5 — 5  shown in FIGS. 2-3; and 
     FIG. 6 is an elevated perspective view of a glide in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A cap  100  in accordance with the present invention is shown in FIGS. 1-5. The cap  100  attaches to a bottom portion of a furniture leg to support an article of furniture, for example a chair, a table, a desk or the like. The cap  100  is thus disposed between the furniture leg and a floor surface upon which the furniture rests so as to facilitate movement of the furniture across the floor surface. 
     The cap  100  is generally circular, and defines an axis  102 . The cap  100  has a generally planar lower surface  110 , an upper surface  120 , and a cylindrical sidewall  130 , and is preferably formed of injection-molded polypropylene plastic. The cap upper surface and sidewall cooperate to define a cup-shaped receptacle that is adapted to receive the furniture leg, as is known in the art. 
     The lower surface  110  (FIG. 2) defines a plurality of first or outer protrusions  140  and a plurality of second or inner protrusions  150 . The outer protrusions  140  are adjacent to the sidewall  130  and spaced from the axis  102 . More particularly, the outer protrusions  140  form a generally circular array that is centered on the axis  102 . The outer protrusions  140  are generally evenly spaced apart from each other, and are each about the same radial distance from the axis  102 . The distal edges of the outer protrusions cooperate to define a first plane  142  that is generally perpendicular to the axis  102  and parallel to the lower surface  110 , as shown best in FIGS. 4 and 5. The outer protrusions  140  thus extend outwardly from the lower surface  110  a predetermine distance or height H 1 . 
     Similarly, the inner protrusions  150  form a generally circular array that is centered on the axis  102  and disposed between the axis  102  and the array of outer protrusions  140 . The distal edges of the inner protrusions define a second plane  152  that is generally perpendicular to the axis  102 , parallel to the lower surface  110 , and disposed between the lower surface  110  and the first plane  142 . The inner protrusions  150  thus extend from the lower surface  110  a distance or height H 2  that is less than the distance or height H 1  of the outer protrusions  140 . 
     In the preferred and illustrated embodiment, there are four inner protrusions  150 , and each of the inner protrusions  150  is connected to a corresponding one of the outer protrusions  140  by a connector or saddle  162 . The saddles  162  extend away from the lower surface  110  and have distal surfaces that cooperate to define a third plane  164 , which is spaced a third distance or height H 3  from the lower surface  110 . The third distance H 3  is less than the first and second distances H 1 , H 2  of the outer or inner protrusions  140 ,  150 , respectively. Thus, the third plane  164  is disposed between the lower surface  110  and the second plane  152 , while the second plane  152  is disposed between the first plane  142  and the third plane  164 . 
     In the preferred and illustrated embodiment, there are eight outer protrusions  140  and four inner protrusions  150 . Thus, four of the outer protrusions  140  are connected to the four inner protrusions  150  by the saddles  162 , as discussed hereinbefore, and the remaining four outer protrusions  140  are not connected to the inner protrusions  150 . The outer protrusions  140  that are not connected to a corresponding inner protrusion  150  are generally teardrop shaped. More specifically, these outer protrusions are connected to an inwardly tapering portion  151  that extends radially inwardly and gently decreases in height until merging with the lower surface  110 , as illustrated. 
     The outer and inner protrusions  140 ,  150 , saddles  162 , and the tapering portions  151  cooperate to define channels  180 . The channels  180  are shaped and arranged to provide paths for dirt and debris to pass beneath the cap  100  as the furniture is moved or slid across a floor surface. Preferably, the arrays of the outer and inner protrusions  140 ,  150  are generally concentric circular rings. The concentric arrangement facilitates alignment of the channels  180  so that dirt and debris can pass through the channels in a generally linear direction. Alternative arrangements of the arrays include rings in which protrusions are staggered or offset relative to each other. 
     The upper surface  120  cooperates with the sidewall  130  to define a generally cup-shaped recess shaped to receive a bottom end of the furniture leg. A lip  190  extends radially inward from the sidewall  130  to further define the recess and to secure or snap-fit to the bottommost portion of the furniture leg. The lip  190  preferably has a beveled inner edge to facilitate or guide a furniture leg into the recess during installation. 
     The cap  100  is designed to be secured to the bottom end of a furniture leg. Generally, the cap  100  is disposed adjacent a bottom end of the furniture leg such that the upper surface  120  is facing the furniture leg end. The cap  100  is then pushed onto the leg such that the leg is received in the cap recess. The furniture leg is then set onto a floor surface with the cap  100  disposed between the leg and the floor, and the lower surface  110  facing toward the floor surface. The outer protrusions  140  engage the floor while the inner protrusions  150  and saddles  162  are vertically spaced from the floor surface. 
     During normal use, the furniture is moved across the floor. The cap  100  supports the furniture and the outer protrusions  140  slide along the floor surface. Dirt and debris on the floor surface pass under the cap lower surface  110  as the cap  100  is slid across the floor surface. In this regard it is noted that the protrusions  140 ,  150  and saddles  162  are relatively rigid such that the protrusions and saddles are capable of supporting the furniture and expected load without deformation thereof. 
     Moving the furniture has the expected effect of wearing down the outer protrusions  140 . As the outer protrusions  140  wear, the height of the outer protrusions  140  decreases such that, eventually, they are equal to the height of the inner protrusions  150 . When the heights of the outer and inner protrusions  140 ,  150  are equal, the outer and inner protrusions  140 ,  150  will both contact the floor surface, while the saddles  162  remain vertically spaced from the floor surface. 
     The outer and inner protrusions  140 ,  150  continue to wear during use. As the heights of the outer and inner protrusions  140 ,  150  further decrease, they eventually are equal to the height of the saddles  162 . When the heights of the outer and inner protrusions  140 ,  150  are about equal to the height of the saddle  162 , the saddles  162  also contact the floor surface. 
     The progressive wear of the protrusions  140 ,  150  serves as objective indication of whether the cap  100  should be replaced. For example, it may be determined that the cap should be replaced when the height of the outer protrusions  140  is equal to that of the inner protrusions  150 . Alternatively, it may be determined that the cap  100  should be replaced when the height of the inner and outer protrusions  150 ,  140  is equal to the height of the saddles  162 . When it is determined that the cap  100  should be replaced, it is simply pulled off the furniture leg and a new cap  100  is installed on the furniture leg, as described hereinbefore. 
     A glide  200  according to a second embodiment of the invention is shown in FIG.  6 . The glide  200  has many parts that are substantially the same as corresponding parts of the cap  100 ; this is indicated by the use of the same reference numbers in FIGS. 1 and 6. The glide  200  differs from the cap  100  in that the glide  200  does not itself snap-fit to the bottommost portion of the furniture leg, but rather has a fastener portion  210  that connects to the furniture leg. 
     The fastener portion  210  which, with the exception of the floor engaging portion described hereinbefore, is generally conventional, and includes a tubular leg portion  212  and a pivotably mounted cup-shaped portion  214  connected to the leg portion  212  by a swivel joint  216 . The leg portion  212  of the fastener portion  210  includes an internal fastener (not shown), by means of which the fastener portion  210  is securely, but releasably, secured to the furniture leg. Various alternative methods for the attachment of glides to furniture legs are known to one of ordinary skill in the art. 
     The cup-shaped portion  214  defines an opening through which a floor-engaging portion having the lower surface  110  extends. Protrusions  140 ,  150  and saddles  162 , as described hereinbefore, project from the lower surface. Thus, the glide  200  is disposed so that, initially, the outer protrusions  140  contact the floor while the inner protrusions  150  and the saddles  162  are vertically spaced from the floor. 
     Similarly to the cap  100 , the glide  200  contacts the floor surface so that, when the article of furniture is slid across the floor, the outer protrusions  140  contact the floor surface. When the outer protrusions  140  are sufficiently worn, the inner protrusions  150  also contact the floor. Further, when the outer and inner protrusions  140 ,  150  are sufficiently worn, the saddles  162  contact the floor simultaneously with the outer and inner protrusions  140 ,  150  to increase the contact area with the floor surface. 
     When the glide  200  is worn, it may be removed from the furniture leg and replaced by a new glide  200 , as is known in the art. Alternatively, the cap  100 , described hereinbefore, may be snapped over the end of the glide  200  so as to cover the glide&#39;s worn lower surface with the cap  100 . 
     Although the cap  100  and glide  200  is disclosed herein as being generally circular, in alternative embodiments, a cap or glide has a different general shape other than a disk shape. For example, the cap or glide may be oval, triangular, or square, in shape. Further, other different suitable materials and fabrication methods for producing the cap or glide are known to one of ordinary skill in the art. For example, the cap may be formed from a different plastic or polymer and the cap or glide may be produced by compression molding or machining, as appropriate. Because the shape or configuration of furniture legs varies from article of furniture to article of furniture, alternative caps and glides in accordance with the invention also vary so as to accommodate or conform to these different furniture leg configurations. For example, some furniture legs require a machine screw to attach to them, accordingly, an alternative cap or glide has a corresponding machine screw so as to attach to those furniture legs. Other alternative caps and glides can attach to furniture legs by spring-loaded clips, inserts, flanged inserts, sleeves, threads, T-nuts, nails and the like. 
     In other alternative embodiments, the number of outer and inner protrusions  140 ,  150  differs, but is generally at least three of each. Additionally, the ratio of saddle-connected to saddle-unconnected outer protrusions  140  differ in other alternative embodiments. 
     In yet another embodiment in accordance with the invention, a first colored pigment is used to color a portion of a cap or glide and a second colored pigment is used to color outer and inner protrusions on the cap or glide. The first and second pigments are used as layers such that the first layer hides the second layer when the cap or glide is new and unused, but when the cap or glide has worn a predetermined amount, the second layer is visible to provide a visual indication that the cap or glide should be placed. 
     While the preferred embodiments have been described and illustrated herein with particularity, it is considered apparent that the present invention is not limited thereto. Rather as noted hereinbefore, with knowledge of the preferred embodiments, one skilled in the art will be capable of various modifications, rearrangements, and substitutions of parts without departing from the scope and spirit of the present invention. Accordingly, the invention is not limited to the preferred embodiments described herein, but rather is only to be defined by the claims appended hereto.