Patent Abstract:
A cable tie with a reduced band thread force is disclosed, comprising an elongate metallic strap, a metallic locking head and a metallic roller means. In one embodiment, the metallic locking head comprising a strap entry notch. In another embodiment, the metallic locking head comprises a strap entry notch and a strap exit notch. In operation, the configuration of the notches, singularly or in tandem, serve to reduce the band thread force in the elongate metallic strap when the elongate metallic strap is inserted into the metallic locking head a second (and subsequent) time.

Full Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/940,762, filed on 30 May 2007. 
    
    
     FIELD OF THE PRESENT INVENTION 
     The present invention is directed to a cable tie having an elongate strap and a locking head and, more particularly, to a metallic cable tie for holding a plurality of articles together in a bundle, while reducing the band thread force present in the elongate strap and allowing for the elongate strap to be fed through the locking head a plurality of times. 
     BACKGROUND OF THE PRESENT INVENTION 
     Metallic bundling devices, such as cable ties, that incorporate locking balls and roller pins have been used for bundling a great variety of items, such as, for example, bales of cotton or a multitude of wires. A common name for these types of cable ties is the “ball lock” or “roller lock” device. In such devices, an elongate metallic strap is wrapped around the objects to be bundled and inserted into a locking head. Contained within the locking head is a metallic ball which, using the shape of the locking head (generally angled towards one end) as well as the force of gravity, lock the elongate metallic strap in place. Gravity also allows the detachment of the elongate metallic strap. By turning the locking head upside down, gravity permits the metallic ball to roll towards the other end of the locking head, thus freeing and allowing the elongate metallic strap to be removed from the locking head. Generally speaking, this process provides a bundling apparatus having a relatively high holding strength. 
     Various means have since been introduced in an effort to further strengthen these types of bundling apparati. One example has been the “double ball” assembly. In this assembly, the properties of two metallic balls combine to provide an even higher holding strength than that available with only one metallic ball. An example of this “double ball” assembly is disclosed in a U.S. Provisional Patent Application No. 60/886,552, entitled “Retained Tension Multiple Ball Lock Cable Tie,” assigned to the same entity as the Assignee of the present invention, and filed on 25 Jan. 2007. The disclosure of this U.S. Provisional Patent Application, as well as its Non-Provisional Counterpart (U.S. patent application Ser. No. 12/018,978, filed on 24 Jan. 2008), are incorporated by reference herein in their entireties. 
     Another example of a means to further strengthen “ball lock” cable ties is the “double loop” assembly. In this assembly, the elongate metallic strap is threaded through the locking head more than one time. The result is a bundling apparatus having a very high holding strength. 
     Both the “double ball” and the “double loop” assemblies provide a heightened level of holding strength. Additionally, both assemblies are adaptable for many uses. 
     However, the “double loop” assembly is not without its drawbacks.  FIG. 1  represents the current state of the art in “double loop” cable tie assemblies. Referring to  FIG. 1 , the initial insertion of the elongate metallic strap into the locking head causes a phenomenon known as “band thread force.” The band thread force results from the fact that the floor of the locking head is flat, while the elongate metallic strap, when wrapped around the bundle of articles, takes on an arcuate form. Thus, the elongate metallic strap does not sit flush against the floor of the locking head. In “single loop” assemblies, this is not a major issue, as the roller means can nevertheless lock into place within the locking head and prohibit the release of the elongate metallic strap from the locking head. However, in “double loop” assemblies, the band thread force makes it difficult to thread the elongate metallic strap in the locking head a second time. 
     U.S. Pat. No. 6,076,235, entitled “Cable Tie” and issued to Wasim Khokhar on 20 Jun. 2000, illustrates one attempt to develop a locking head that provides a reduction in the band thread force. In the locking head disclosed in the &#39;235 patent, a notch was formed in the floor of the locking head proximate the strap entry face. This provided for a slight release of the band thread force within the locking head. U.S. Pat. No. 4,765,032, entitled “Environmental Bundling Tie,” and issued to William A. Fortsch on 23 Aug. 1998, also attempted to solve the band thread force problem by employing a similar solution. Both disclosures of the &#39;235 and the &#39;032 patents are hereby incorporated by reference in their entireties. 
     Although the above references attempted to provide a solution to the problem of the band thread force, a substantial reduction in the band thread force did not result, and the issue still remains. Thus, it would be desirable to provide a “double loop” cable tie assembly having a substantially-reduced band thread force that overcomes the disadvantages in the previously disclosed devices. 
     SUMMARY OF THE PRESENT INVENTION 
     A cable tie with a reduced band thread force is disclosed, comprising an elongate metallic strap, a metallic locking head and a metallic roller means. In one embodiment, the metallic locking head comprises a strap entry notch. In another embodiment, the metallic locking head comprises a strap entry notch and a strap exit notch. In operation, the configuration of the notches, singularly or in tandem, serve to reduce the band thread force in the elongate metallic strap when the elongate metallic strap is inserted into the metallic locking head a second (and subsequent) time. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  illustrates a side view of the current state of a metal cable tie adaptable for a “double loop” assembly; 
         FIG. 2  illustrates a perspective view of a metal cable tie, manufactured in accordance with the tenets and teachings of the present invention shown secured around a bundle of wires; 
         FIG. 3  illustrates a perspective view of the locking head of the metal cable tie of  FIG. 2 ; 
         FIG. 4  illustrates a side sectional view of the elongate strap and the locking head of the metal cable tie of  FIG. 2 ; 
         FIG. 5  illustrates an underside perspective view of the locking head of the metal cable tie of  FIG. 2 ; 
         FIG. 6  illustrates a front sectional view of the elongate strap and the locking head of the metal cable tie of  FIG. 2 ; 
         FIG. 7  illustrates a top perspective view of the metal cable tie of  FIG. 2 ; 
         FIG. 8  illustrates a perspective view of an alternate embodiment of the locking head of the metal cable tie of  FIG. 2 ; and 
         FIG. 9  illustrates a side sectional view of an alternate embodiment of the elongate strap and the locking head of the metal cable tie of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The illustrated embodiments of the present invention are directed to a three-piece cable tie that uses a combination of a roller means and a locking head to secure an elongate strap therein. 
     Referring now to the Figures, in which like elements are represented by the same reference numerals, a cable tie for bundling a plurality of elongate objects, such as wires  12 , and for holding those elongated objects together, is generally indicated in  FIG. 2  by reference numeral  10 . Cable tie  10  preferably includes locking head  14  and roller means (not visible in  FIG. 2 ). As more clearly illustrated in  FIGS. 3-9 , locking head  14  preferably receives first end  16  of elongate strap  18 , and is adapted to additionally receive second end  20  of elongate strap  18 . Additionally, second end  20  of elongate strap  18  may be inserted into locking head  14  a subsequent time. As is illustrated by the Figures, elongate strap  18  is fed through locking head  14  in such a manner that there is no secure connection between locking head  14  and elongate strap  18 . Nevertheless, the tenets and teachings of the present invention will be achieved, as the insertion of elongate strap  18  into locking head  14  a second (and any subsequent) time will prevent the unraveling of elongate strap  18 , based on the effects of friction between the portions of elongate strap  18  in contact with each other, as well as the effects of both gravity and geometry on roller means  22 . Alternatively, as is illustrated by  FIG. 4 , first end  16  of elongate strap  18  may be secured to locking head  14  by any known means. Roller means  22  is preferably illustrated in the form of a ball or sphere-like object, most clearly illustrated in  FIG. 4 , for retaining elongate strap  18  within locking head  14 . 
     Roller means  22 , locking head  14  and elongate strap  18  each can be formed of stainless steel—or any other suitable material, including both other metals and plastics—to allow the devices to be used over a wide temperature range and to give cable tie  10  both a high strength and an excellent resistance to corrosion. Additionally, by means currently known in the art, elongate strap  18  may be selectively coated with any known corrosion-resistant coating, such as that disclosed in U.S. Pat. No. 5,103,534 or U.S. patent application Ser. No. 10/794,613, the disclosures of which are hereby incorporated herein by reference in their entireties. Further, elongate strap  18  may also be color coded, according to OSHA safety standards. Moreover, the surface of roller means  22  can be textured or roughened to increase its friction coefficient with the other elements of cable tie  10  (i.e., locking head  14  and elongate strap  18 ). 
       FIGS. 3-7  illustrate one embodiment of locking head  14 , in accordance with the tenets and teachings of the present invention, in more detail. Referring to  FIGS. 3-7 , locking head  14  is illustrated as generally comprising strap entry face  24 , strap exit face  26 , retention means  28 , first side wall  30 , second side wall  32 , floor  34  and roof  36 . 
     Floor  34  and roof  36  are preferably joined by first side wall  30  and second side wall  32 . This is illustrated most clearly in  FIG. 6 . In doing so, these elements define strap-receiving aperture  38 , which extends the length of locking head  14  between strap entry face  24  and strap exit face  26 . Referring back to  FIGS. 3-6 , it is illustrated that roof  36  diverges in the direction of floor  34  as locking head  14  progresses from strap entry face  24  to strap exit face  26 . 
     Additionally with reference to floor  34 , it is illustrated that floor  34  defines strap entry notch  40 . Strap entry notch  40  comprises an indentation within the bottom portion of strap entry face  24 . The size of the indentation, which reduces the overall length of floor  34 , allows a substantial release of the band thread force, thus making it easier to insert elongate strap  18  into strap entry face  24  a subsequent time. As shown in  FIG. 4 . the result of the band thread force, shown as open area  42 , is greatly reduced. The reduction in open area  42  provides for a greater strap-receiving aperture  38 , which allows elongate strap  18  to be inserted into locking head  14  a second (and subsequent) time. 
     Regarding the locking of cable tie  10 , as more closely illustrated in  FIGS. 4 and 7 , roller means  22  is captively held between roof  36  and floor  34  by retention means  28 . Retention means  28  comprises finger  44  extending from roof  36  towards floor  34  adjacent strap exit face  26 . 
     It is contemplated that roller means  22  is movable between a threading position, not illustrated in the Figures, wherein roller means  22  is disposed as engaging finger  44 , and proximate to strap exit face  26 , and a locking position, wherein roller means  22  is closer to strap entry face  24  and securely engages elongate strap  18 . In the threading position, roller means  22  concurrently engages finger  44  and roof  36 . 
     In operation, and once again referring to the Figures, after elongate strap  18  is wrapped around the objects (e.g., wires  12 ) to be held, second end  20  of elongate strap  18  is inserted into locking head  14 . Continued threading of elongate strap  18  results in positive engagement of elongate strap  18  with roller means  22  at any angle locking head  14  is held. As a result of the strength and nature of elongate strap  18 , a positive band thread force will be exerted upon by elongate strap  18 , thrusting elongate strap  18  up from floor  34  of locking head  14 , through strap-receiving aperture  38  and towards roof  36  of locking head  14 . In some instances, this band thread force may make it extremely difficult to insert second end  20  of elongate strap  18  into locking head  14  a second time. However, due to the placement of strap entry notch  40 , the positive band thread force is reduced, allowing a user to more easily insert second end  20  of elongate strap  18  into locking head  14  a second time. 
     In an alternate embodiment, as illustrated in  FIGS. 8-9 , strap entry notch  40  may be reduced in length, and locking head  14  is provided with strap exit notch  46 . In this embodiment, strap entry notch  40  and strap exit notch  46  combine to comprise indentations within the bottom portion of strap entry face  24  and strap exit face  26 . Similar to the embodiment described above, the size of the indentations, which reduces the overall length of floor  34 , allows a substantial release of the band thread force, thus making it easier to insert elongate strap  18  into strap entry face  24  a subsequent time. Again, similar to the embodiment described above, as shown in  FIG. 9 , the result of the band thread force, shown as open area  44 , is greatly reduced. Thus, the reduction in open area  42  provides for a greater strap-receiving aperture  38 , which allows elongate strap  18  to be inserted into locking head  14  a second (and subsequent) time. 
     The disclosed present invention provides a cable tie that allows for a reduction in the band thread force. It should be noted that the above-described and illustrated embodiments and preferred embodiments of the present invention are not an exhaustive listing of the forms such a cable tie in accordance with the present invention might take: rather, they serve as exemplary and illustrative of embodiments of the present invention as presently understood. Many other forms of the present invention exist and are readily apparent to one having ordinary skill in the art.

Technology Classification (CPC): 8