Abstract:
A tamper-evident fastening assembly for an outlet of a conduit, including a closure member for covering the outlet of the conduit, a strap extending from the closure member, and first and second fasteners connected to the closure member. The first fastener secures a first portion of the strap to the conduit by forming a first loop. The second fastener secures a second portion of the strap to the closure member by forming a second loop. Removal of the closure member from the outlet breaks the second loop but leaves the first loop intact on the conduit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention generally relates to a tamper-evident fastening assembly and a method for sealing an outlet of a conduit with the fastening assembly such that end users can readily tell if the outlet has been opened previously. 
     2. Description of Related Art 
     Tamper-proof caps are well known and commonly used in industrial applications. Such caps include a plug for closing an outlet and a one piece-molded flexible strap attached at one end to the plug and having a locking mechanism integral with the plug. The strap also includes at least one tooth at its free end to irreversibly insert into the locking mechanism. The strap forms a tight closed loop around a conduit with the plug covering the outlet. The strap must be broken in order to gain access to the outlet, thereby protecting the outlet before it is used and evidencing prior use or tampering if the strip is broken. See U.S. Pat. No. 5,397,012 to Tyson et al. for an example of a tamper-proof sealing plug assembly, the disclosure of which is herein incorporated by reference. 
     SUMMARY OF THE INVENTION 
     However, a problem exists in the industry in that those outlets which have tamper-evident covers do not include any structure that remains after the cap is first removed. Therefore, once removed, the purchaser or user has no idea whether a cap was previously located in or on the outlet. This causes uncertainty on the part of the customer or user because of the lack of tamper-proofing. 
     Therefore, it is the object of this invention to produce an economic, easily-used outlet sealing assembly which provides tamper evidence. The device has a cap sized to cover the outlet and a strap connected to the cap. The strap has a plurality of locking mechanisms for irreversible insertion into a first locking mechanism. The strap is looped around the conduit and this first loop is tightened by inserting the strap through the first locking mechanism. A second locking mechanism is also provided so that the strap can be formed into a second loop around the conduit and then irreversibly inserted into the second locking mechanism after insertion through the first locking mechanism. The device thereby forms a double loop when engaged. The second loop is broken on first use to remove the cap. This leaves the first loop intact as evidence of tampering and retains the cap to the conduit and can be reused to protect the outlet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention and its advantages will be better understood in relation to the following drawings in which like reference numerals refer to like elements and wherein: 
     FIG. 1 is an example of a tamper-evident fastening assembly after manufacture and before use; 
     FIG. 2 illustrates the fastening assembly with a first locking mechanism engaged to form a first loop; 
     FIG. 3 illustrates the fastening assembly with a second locking mechanism engaged to form a second loop; 
     FIG. 4 illustrates the fastening assembly after first use where the second loop is broken; 
     FIG. 5 illustrates the fastening assembly with both locking mechanisms engaged and with the strap wrapped around a conduit with the cap covering the outlet. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 illustrates an exemplary embodiment of the tamper-evident fastening assembly as manufactured and before mounting or use on a conduit. Preferably, the assembly is a one piece molded plastic assembly, but other materials could be used. The assembly includes a closure assembly (cap)  10  sized to fit over an outlet of a conduit. The shape and/or size of the cap is variable depending on the size and/or shape of the outlet to be covered. The cap friction fits over the outlet and protects it from dust or damage while, for example, the conduit (or container on which the conduit is mounted) is being transported, stored or installed. If desired, the cap can be sized to seal or plug the outlet to prevent entry of substances into the conduit and/or to prevent exit of substances from the conduit. 
     The cap  10  includes a strap  16  extending from one side of the cap. The strap has one end connected to the cap and an opposite free end  16 A. The length of the strap is variable depending on the size of the conduit to which it will be attached. In an exemplary embodiment, the strap is about 11 inches or 28 cm long, but longer or shorter straps are possible. 
     A first fastener  14  is provided in the strap  16 . The first fastener  14  preferably has a hole  14 A through which the free end  16 A of the strap  16  can be inserted to form a first loop  18  (see FIG.  2 ). The fastener  14  secures a first portion of the strap that defines the first loop. In an exemplary embodiment, the strap has a plurality of projections such as teeth  16 B which engage with locking members  14 B that surround the hole  14 A in the first fastener  14 . The locking members  14 B allow the teeth  16 B to pass through the fastener when the free end  16 A of the strap is inserted in the hole  14 A and the strap  16  is drawn through the fastener  14 . However, the locking members  14 B prevent the teeth  16 B from passing in the opposite direction to withdraw the strap  16  from the fastener  14 . Therefore, the strap  16  is irreversibly inserted into the fastener  14  to form the first loop  18 . 
     As illustrated in FIGS. 2 and 5, the first loop  18  can be of any size. However, it is preferred that the strap  16  is drawn through the first fastener  14  to such an extent that the first loop is tightly wound around the conduit  22  illustrated in FIG.  5 . 
     The first fastener  14  is preferably located on the strap  16 , preferably a distance of about 2-3 inches or 6-7 cm from the cap. This distance is variable, but should be long enough to allow the strap to wrap around the conduit and to attach or remove the cap from the outlet  22   a  illustrated in FIG.  5 . The portion of the strap between the first fastener  14  and the cap  10  can be a retaining portion  16 D that retains the cap  10  on the conduit by virtue of its retaining portion  16 D being attached to the first loop  18 . However, the first fastener  14  could be located elsewhere on the assembly as long as it is secured to the cap  10 . 
     A second fastener  18  is also located on the cap  10 , and preferably has the same construction as the first fastener  14  (i.e., hole  18 A surrounded by locking members  18 B that engage the teeth  16 B on the strap  16 ). As illustrated in FIGS. 3 and 5, the free end  16 A of the strap  16  is irreversibly inserted into the second fastener  18  to form a second loop  20 . A second portion of the strap is defined as the portion of the strap in the second loop between the first and second fasteners  14 ,  18 . The second portion of the strap  16  is wound around the conduit  22  and inserted into the second fastener  18  to form the second loop  20 . 
     In operation, as illustrated in FIGS. 2-5, the cap  10  is placed on the outlet  22 A and the free end  16 A of the strap  16  is wound around the conduit  22  and inserted into the first fastener  14  to form the first loop  18  (FIGS.  2  and  5 ). The strap is drawn through the first fastener  14  such that the first loop  18  forms a tight friction fit around the conduit  22 . The free end  16 A of the strap  16  is then wound around the conduit  22  and inserted into the second fastener  18  to form the second loop  20  (FIGS.  3  and  5 ). The strap  16  is then drawn through the second fastener  18  such that the second  20  loop forms a tight loop that prevents the cap  10  from being removed from the outlet  22 A (FIG.  5 ). 
     When it is time to remove the cap  10  from the outlet  22 A, the second loop is broken (FIG.  4 ). In an exemplary embodiment, the strap  16  can include a frangible element  16 C near the free end  16 A of the strip. The frangible element  16 C allows for readily breaking the second loop  20 . When the second loop is broken, the cap  10  can be removed from the outlet  22 A but remains attached to the conduit via the retaining portion  16 D. 
     When the second loop is broken, there is a visual indication that the cap may have been removed from the outlet  22 A. Further, even when the second loop is broken, the first loop remains intact. The assembly therefore has the advantage that: 1) the first loop remains on the conduit—even if the second loop and fastener portion of the strap are cut away, there is still a visual indication remaining (i.e., the first loop  18 ) that the outlet  22 A has been exposed; and 2) the first loop retains the cap in an accessible position (via the retaining portion  16 D) where it could be reattached to the outlet  22 A for reuse. 
     It is noted that the second fastener  18  can be attached to the cap  10  via an extension  18 C, or can be located directly on the cap  10 . When the extension  18 C is used, the second fastener  18  can be spaced back from the end of the extension to form a gripping portion  18  that allows the user to easily grip the cap for attachment to or removal from the outlet  22 A. It is also noted that a frangible element could be provided in the extension  18 C to assist in breaking the second loop. 
     While this invention has been described in conjunction with specific embodiments outlined above, it is evident that many alternative, modifications and variations will be apparent to those skilled in the art. For example, other types of fasteners could be used. Also, the fasteners could be separate elements from the strap, instead of the one-piece construction described above. Accordingly, the preferred embodiments of the invention as set forth are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined herein.