Patent Publication Number: US-2015084235-A1

Title: Overmolding buckles at the same time as overmolding a lens respirator

Description:
This Divisional Application is based on U.S. application Ser. No. 12/925,446 filed on Oct. 21, 2010 which in turn is based on U.S. Provisional Application #61/280,063 filed on Oct. 29, 2009 by Eric P. Rose for Overmolding Buckles At The Same Time As Overmolding Lens Respirator. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention is in the field of respirators used for personal protection. Respirators require an attachment means which allow the respirator to be affixed securely to the user&#39;s face. In most reusable respirators, this attachment means is accomplished through the use of a plurality of buckles which connect the mask body to a harness. These buckles typically have an adjustments means which allows a user to adjust the fit of the mask body to the face as needed depending on the size and shape of their face. Respirator manufactures have used several techniques of inserting buckles into a respirator. Most often this is achieved by means of a rivet that extends through a tab on a mask&#39;s flange and simultaneously through a buckle. Secondarily, a separate harness may be strung through the buckle allowing for an adjustment means of securing the mask to the face. This joint assembly of flange tab, rivet, buckle, and harness may be repeated a plurality of times on the mask as desired by the manufacturer. 
     The common method of attaching a mask body to a harness through the system of rivet and buckle as noted above has numerous shortcomings. Market research has shown, and one skilled in the art would understand that, over time and with repeated use the rivet joint will loosen up and is likely to come apart. During use of the respirator, typically in hazardous environments, such loosening or unintended disassembly could possibly be hazardous to the user&#39;s health. From a load distribution perspective in this joint, the typically small rivets and the corresponding hole they require in the flange&#39;s tab offer relatively little surface area to carry the load in the joint. With such a traditional multipart assembly, significant costs would be incurred to produce and assemble the individual parts. This manufacturing cost results in a higher cost of the respirator to the user which may limit the availability of the product. Also with such a multipart assembly, the product is big, bulky and obtrusive and less aesthetically appealing. 
     SUMMARY OF INVENTION 
     The invention described herein is novel for several reasons and is a significant improvement over prior art. This invention is one where the buckles used to attach the mask body to the harness are integrally molded to the flange&#39;s tabs at the same time as the flange itself is molded to the respirator&#39;s lens. The molding of the flange to the lens is part of a prior patent application Ser. No. 12/284,133 filed Sep. 18, 2008 and is assigned to the same assignee as the instant application. The flange would generally be injection molded and the molding material may be thermoplastic rubber but other materials such as silicone or even compression-molded rubber, or the like could be used. 
     This invention is novel and an improvement over prior art and the prior application referenced above for several reasons. First, because there is no rivet in the assembly there is no chance of such a joint loosening over time and extended use. Second, the invention uses a broad surface area between the flange tabs and the buckle portions so as to insure a firm connection. The buckle portions may also include openings extending through the buckle portions so that the molding of the flange tabs also may be through the openings to further secure the connection between the flange tabs and the buckle portions. 
     The present invention is simpler in construction, simpler in manufacturing and lower in cost due to fewer parts and less hand assembly than the prior art devices. 
     A clearer understanding of the invention will be had with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates the component parts of the respirator to be assembled during the molding of the flange, 
         FIG. 2  illustrates the component parts of the respirator assembled by the molding of the flange, 
         FIG. 3  illustrates the component parts of the respirator positioned in a two-piece mold, and 
         FIG. 4  illustrates the assembled parts of the respiration positioned in the mold after molding the flange. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     As illustrated in  FIG. 1 , the component parts of the respirator include a lens  10 , two upper buckle portions  12  and two lower buckle portions  14 . As can be seen in  FIG. 1  both upper and lower portions  12  and  14  include openings there through  16  which assists during the molding of a flange member interconnecting the lens  10  and the buckle portions  12  and  14 . 
       FIG. 2  illustrates a completed respirator after molding flange. Specifically as shown in  FIG. 2  a flange member  18  is overmolded to the lens  10  and the buckle portions  12  and  14 . The overmolding of the flange to the lens  10  is fully described in the previously referenced patent application assigned to the same Assignee as the instant application. The overmolding of the flange is accomplished with tab portions  20  extending from the flange  12  and with these tab portions encapsulating the upper and lower flange members in the area of these flange members that include the openings  16 . The mold material will flow through the openings to lock the buckle portions in position. In addition, the tab portions  20  overlay part of the upper and lower buckle portions over a broad area to also ensure a secure engagement between the tab portions  20  and the buckle portions  12  and  14 . 
       FIG. 3  illustrates the same components parts shown in  FIG. 2  but positioned within a two-piece mold member  22 . As can be seen the two-piece mold member has a mold cavity  24  in dotted line which is the same shape as the flange member  18  shown in  FIG. 2 . Injection ports  26  extend through the two-piece mold  22  and with an injection molding equipment  28  attached to the ports for injection molding thermoplastic material into the mold cavity  24 . 
       FIG. 4  illustrates the assembled respirator located within the two-piece  22  and as shown by arrows  30  the mold may be split along the direction of the arrows  30  so that the assembled respirator can be released from the mold. It will be appreciated that other component members can then be attached to the assembled respirator including harness members attached to the buckle portions and other accessories attached to the lens for completion of a full face respirator. 
     It will be appreciated that other variations and modifications may be made to the invention as described without deviating from the spirit of the invention as described above.