Abstract:
A durable, reusable routing envelope is provided that is environmentally friendly and provides a greatly extended lifetime compared to routing envelopes in current use.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to providing durable, reusable, and thus environmentally friendly, envelopes in situations such as interoffice mail. 
       BACKGROUND OF THE INVENTION 
       [0002]    Routing envelopes are used in large numbers for interoffice mail or other deliveries by government agencies, colleges and universities, and other entities such as corporations. These envelopes typically provide a pocket for containing the papers or other items to be transferred from one person or department to another, and a space on the face of the envelope for writing in the destination of the envelope. Often, the face of the envelope provides a series of horizontal lines; when the envelope is re-used, the prior destination is “deleted” by marking through it, and the new destination or recipient written in on the next available line. 
         [0003]    While such envelopes are reusable to a limited extent, they are typically disposed of when all the address lines have been used, or earlier if the envelope is already worn out from handling. Previous attempts have been made to “renew” the lifetimes of such envelopes. U.S. Pat. No. 5,779,137 to Coffey discloses a reusable envelope with a replaceable address label. The address label of Coffey must be replaced in its entirety when all of the address spaces have been used, but its use extends the lifetime of an envelope that is otherwise serviceable. 
         [0004]    Similarly, U.S. Pat. No. 3,856,198 to Daley discloses a reusable envelope with a front pocket to hold a pad of ruled sheets. Each sheet in the pad of the Daley disclosure provides a series of address spaces, with the intention that when a sheet is filled, the pad should be removed from the pocket, the top sheet discarded, and the pad then should be replaced in the pocket. Depletion of the entire pad requires a new address pad, a process that can continue until the envelope wears out. 
         [0005]    However, in each of these prior disclosures, the envelope material must be sufficiently rigid to provide structure to the envelope itself. In the disclosure of Daley, for example, the construction of the envelope is disclosed as making certain folds in a single piece of stock. Because these envelopes must be expected to withstand repeated day-to-day handling, the material that provides the envelopes structure is subject to continual wear, and must eventually be replaced. 
         [0006]    Replacement of envelopes, especially at an institution or agency with a high-volume of interoffice mail, can require a large regular expenditure. Additionally, the “expired” envelopes must either be disposed of or recycled. Both options require an environmental cost; the choice is between the space and energy devoted to refuse disposal, such as a landfill, or the energy cost of recycling, new packaging, etc. 
         [0007]    Accordingly, it is desirable to provide a reusable routing envelope that can have an extended lifetime compared to present envelopes, thus providing an envelope that is more environmentally friendly. It is further desirable to provide such an envelope that requires no periodic replacement of its component parts. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention is a routing envelope constructed primarily from a durable, flexible material, preferably a nonwoven polypropylene. Nonwoven polypropylene provides significantly better wear resistance compared to the paper or cardstock materials presently used for routing envelopes. In addition to its excellent durability, nonwoven polypropylene is light-weight, resists tearing, and yet is easily workable. 
         [0009]    Those of skill in the art will recognize that other materials with similar durability may also be used without departing from the spirit of the invention. For example, some versions of the polyethylene products marketed under the trade name Tyvek® may be suitable for this application. 
         [0010]    In a preferred embodiment, the routing envelope of the present invention comprises two essentially rectangular pockets. A first pocket is formed entirely by the flexible, durable material and is closable by a secureable flap. In a preferred embodiment, the closure for the flap will be a button-and-string closure, allowing the flap to be secured or opened quickly while simultaneously providing security against loss of the envelope&#39;s contents during handling. Other closures may also be used, for example, button-and-hook fasteners, such as those marketed under the trade name Velcro® may be used. The only constraint on the closure is that, like the envelope&#39;s material, the closure should be durable and capable of long-term, repeated use without failure. 
         [0011]    The second pocket of the envelope comprises an essentially transparent section, allowing a routing sheet to be slid into place in the second pocket so that the destination address is clearly visible. The essentially transparent section of the first pocket is preferably formed with essentially transparent, lightweight plastic. The plastic is less flexible than the flexible, durable material of the envelope, and thus provides structural support to maintain the shape of the envelope when it is empty. 
         [0012]    The routing sheet may be a traditional style, providing spaces to write in successive addresses, or as simple as a single sheet showing the “To:” address. Because the routing sheet is easily and immediately replaceable with any sheet of plain paper, there is no need for pre-printed forms. If a multi-entry routing sheet is used to conserve paper and is filled up, it may be replaced in seconds with a new one produced on any local printer. Thus, the invention allows the display of routing information without the need for pre-printed forms or adhesives. 
         [0013]    The second pocket may also be provided with a means of securing it in a closed configuration, but one is generally not necessary. If so desired, a means for securing the second pocket could be fashioned in any of a number of ways apparent to those skilled in the art, such as by providing a hook-and-loop closure, providing a second flap to secure the second pocket, or even utilizing the same flap to secure both the first and second pockets. Such variations may be made without departing from the spirit of the invention. 
         [0014]    In the preferred embodiment, three sides of both the first and second pockets are permanently secured, and preferably so secured by stitching along three sides of a rectangularly configured envelope. This construction allows for each pocket to have one open side for insertion of documents into the first pocket and a routing slip into the second pocket. A securable flap is preferably provided to hold the open side of the first pocket closed, thus securing the contents of the first pocket in the envelope during routing. Alternative methods of holding the openable side of the first pocket closed may be used without departing from the spirit of the invention. Similarly, alternative construction of the envelope pockets, such as by making two or more sides of either pocket openable, may be utilized, although these embodiments are not preferred as they would increase the cost of manufacture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1A  is an elevational view of one side of an embodiment of the invention. 
           [0016]      FIG. 1B  is a cross-sectional view of the embodiment of the invention shown in  FIG. 1A . 
           [0017]      FIG. 1C  is an elevational view of a second side of the embodiment of the invention shown in  FIG. 1A . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to  FIGS. 1A ,  1 B, and  1 C, an embodiment of the invention is a two-pocket envelope  10 . Envelope  10  comprises a first pocket  12  and a second pocket  14 . First pocket  12  is securable by folding flap  16  over first pocket open end  18 , and securing flap  16  in position, for example by use of releasable closure  20 . Releasable closure  20  is preferably a string-and-button closure and comprises first button  22 , second button  24 , and string  26 , and can be repeatedly used to releasably secure flap  16 . 
         [0019]    Those of skill in the art will recognize that other releasable closures may be used without departing from the spirit of the invention. For example, hook-and-loop closures, such as those marketed under the trade name Velcro®, may be used. 
         [0020]    Alternatively, flap  16  could be attached to, or be made part of, first side  28  of envelope  10 , and be releasably securable over both first pocket open end  18  and second pocket open end  19 . However, securing second pocket open end  19  is not required. 
         [0021]    First side  28  of envelope  10  is preferably secured along three edges, for example by edge stitching  30 . Those of skill in the art will recognize that other means for securing these edges, such as adhesives, maybe used as a matter of engineering or design choice. Additionally, hem stitching  32  may be used to form a hem to protect the edge of the material at top edge  34  of first side  28 , but unlike edge stitching  30  would not penetrate intermediate side  36  of first pocket  12 . 
         [0022]    Second side  38  of envelope  10  comprises an essentially transparent section  40 . Like first side  28 , second side  38  is preferably secured along three edges, and this is preferably accomplished by having edge stitching  30  penetrating both first side  28  and second side  38 . Also like first side  28 , second side hem stitching  42  may be used to form a hem at top edge  44  of second side  38 . 
         [0023]    Except for essentially transparent section  40 , envelope  10  comprises a flexible, durable material, preferably a nonwoven polypropylene. These preferred materials are extremely wear resistant and durable, but are essentially cloth-like, and provide little, if any structural support to keep envelope  10  flat, especially when empty. Essentially transparent section  40  is preferably a transparent plastic of greater rigidity than the flexible, durable material that forms the body of envelope  10 . Essentially transparent section  40  thus assists the structure of envelope  10  to retain its preferred shape for better ease of handling. 
         [0024]    In use, materials to be transferred are placed in first pocket  12  through first pocket open end  18  and secured therein by securing flap  16  with closure  20 . A routing slip (not shown) is inserted in second pocket  14  through second pocket open end  19  so that the routing information is visible through essentially transparent section  40 . 
         [0025]    The above descriptions are provided by way of example only and do not limit the scope of the invention. Those of skill in the art will recognize that variations can be made without departing from the spirit of the invention that is claimed below.