Patent Publication Number: US-2009227431-A1

Title: Weight Plate

Description:
References Cited: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                 7,300,389 
                 Nov. 27, 2007 
                 Lien; Louis (Bellaire, TX) 
               
               
                 7,198,591 
                 Apr. 3, 2007 
                 Lien; Louis (Bellaire, TX) 
               
               
                 6,746,380 
                 Jun. 8, 2004 
                 Lien; Louis (Bellaire, TX) 
               
               
                 6,736,765 
                 May 18, 2004 
                 Wallace; Richard S. (Thousand Oaks, CA), 
               
               
                 6,319,176 
                 Nov. 20, 2001 
                 Landfair; Craig D. (Ventura, CA) 
               
               
                 5,853,355 
                 Dec. 29, 1998 
                 Standish; Victor J. (Lancaster, PA) 
               
               
                   
               
            
           
         
       
     
     FIELD OF THE INVENTION 
     The invention relates to physical fitness equipment, and more particularly a weight lifting plate manufactured by parts and integrated into a whole weight plate. 
     BACKGROUND OF THE INVENTION 
     Barbell set is a typical choice of physical exercises especially for free-weight lifting. Generally, a barbell set includes an elongated rigid bar for grasping with one or both hands and having removable weight plates at each end. The weight plates are typically included as a collection of plates for selective installation on the bar according to the user&#39;s ability. Conventional weight plates are constructed of metallic material. One example disclosed in U.S. Pat. No. 7,300,389, describes a weight plate wholly constructed by cast iron. The plate is disc-shaped, and formed with a central throughbore sized to slidably receive the end of the bar. Unfortunately, the wholly cast weight plate has rough surface and inaesthetic look therefore requires extra finishing steps to place the product in a saleable state such as de-burring operations to finish the edges of the throughbore and the plate periphery. Further steps often involved in manufacture of metallic plates include chroming the plate to achieve an appealing aesthetic finish, and coating the plate with a thermoplastic compound which increased the manufacturing cost. The manufacturing process causes pollution to the environment and considerable energy consumption. The disused weight plate has to be collected and meltdown before it can be used again. 
     SUMMARY OF THE INVENTION 
     Compared with conventional integrally formed weight plates which require many finishing steps, the present invention provides a novel method to manufacture a kind of weight plate with smooth surface and reduced manufacturing cost. To realize the advantages above, the invention comprises a weight plate including a plate body formed with a central throughbore and having a plate periphery. The body is further formed with upper and lower circular trough shells and an annular core fits tightly into both trough shells. The corresponding edges of the shells are sealing connected and formed a whole piece of weight plate. 
     The present invention is not integrally formed. The upper and lower shells are manufactured with metal sheet, which creates a smooth surface and aesthetic appearance. The number of finishing steps necessary to fabricate the plate including deburring rough edges, chroming or coating the plate with a thermoplastic compound may be minimized, and consequently the associated manufacturing costs. 
     The core element of the present invention can be constructed of ore powder with appropriate particle diameters and adhesives into shape. The core element is fits tightly into the upper and lower shells, the corresponding edges of which are sealing connected, and are integrated into a whole piece of weight plate. The manufacture process is energy-economizing and hardly causes pollution to the environment. Weights plate of varying weights and specifications are made possible by density calculation of the shell and core material and adjusting the diameter and width of the weight plates. Shells and cores of the disused weight plates can be recycled and directly put to use again. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a plan view of the weight plate of the invention looking from the top of the weight plate. 
         FIG. 2  is an edge detail, cut-away view of the weight plate, looking from the side of the weight plate shown in  FIG. 1  along line A-A. 
         FIG. 3  is an elevation view of the weight plate looking from the side. 
         FIG. 4  is a cross-sectional view of the weight plate of  FIG. 3  along lines B-B. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 1-4 , the weight plate of the present invention, generally designated  10  includes a substantially circular plate body  11  having hole(s) including a central through-bore  12 . The plate body  11  is further formed with upper circular trough shell  20  and lower circular trough shell  21  (see  FIG. 4 ) and an annular core  30  between the upper and lower shells that fit tightly into both trough shells. The corresponding edges (inner edge  1  and outer edge  2 ) of said trough shells are sealing connected with each other and enclose the core to form a whole piece of annular plate body  11 . 
     The detailed technical solutions of the present invention include:
         1. Said upper shell  20  and lower shell  21  of said weight plate  10  is formed of 0.05 mm to 10 mm metallic sheet (e.g. steel sheet, aluminum alloy Sheet, and other metallic alloy sheets). Metallic sheets were pressed into shape.   2. Said core  30  of the weight plate is formed of ore powder and adhesives by compressing and solidifying into shape. Said ore powder the particle diameter of which ranging from mesh  2  to mesh  800  is iron ore powder, crap iron powder, or concentrated ore powder.   3. Said corresponding edges of the upper and lower shells (inner edge  1  and outer edge  2 ) are sealing connected by welding.       

     In one preferred embodiment of the present invention: the material density of the shells and cores is calculated to form a five-pound weight plate having a one-inch (25.4 mm) diameter central through-bore. The example adept 1.5 mm steel sheets were pressed into circular troughs to form the upper and lower shells of the weight plate as illustrated by  FIG. 4 . Diameter of the central opening is one-inch (25.4 mm). Each circular trough has an outboard diameter of 190 mm and a width of 23 mm. The core element of said weight plate is formed of mesh  400  to mesh  500  iron ore powder with a specific gravity of 65% iron ore powder is mixed with polyvinyl acetate emulsion adhesive and further compressed into a circle having an outboard diameter of 190 mm, an inboard diameter of 28 mm and a width of 23 mm. The core element fits tightly into the upper and lower trough shells. The corresponding edges of said trough shells are sealing connected by argon arc welding with each other and enclose the core to form a whole piece of annular weight plate body. 
     While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.