Abstract:
A flexible tie strap includes an elongated narrow web with a fastener joined at one end. One surface of the web is equipped with a plurality of spaced apart ratchet teeth. The fastener includes an aperture to receive the free end of the web and a tongue with a pawl. The pawl is positioned to engage the web teeth to prevent withdrawal of the web through the fastener. A release tab and an anchor tab are joined to the fastener in spaced relation to each other for flexing the fastener to disengage the pawl from the teeth and release the strap from the fastener. The web of the strap may include a series of spaced apart holes to permit attachment of other devices to the strap.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims priority under 35 U.S.C. § 119(e) and 37 C.F.R. 1.78 (a) based upon copending U.S. Provisional Patent Application No. 60/443,145 entitled Flexible Tie Strap, which was filed on Jan. 27, 2003. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention is broadly concerned with a flexible tie strap used for supporting pipes, ductwork, wiring or the like. More particularly, it is concerned with a flexible tie strap having an adjustable fastener with a release mechanism for securing the tie strap to itself or to another strap.  
           [0003]    Flexible tie straps are commonly employed to rig and support ductwork for heating, ventilating and air conditioning (HVAC) systems. They are also used as cable ties to support electrical wiring and fiberoptic cables. Such tie strap devices are typically of ratchet and pawl construction with parallel entry of a free end of the strap through a buckle member to form a loop which is used to encircle and support a pipe, duct or cable. One side of the strap includes ratchet teeth and the buckle member is equipped with a pawl. The free end of the strap is inserted through the buckle member and the pawl rides over the teeth as the strap is pulled through the buckle. The shoulder of the ratchet tooth adjacent the pawl locks the strap against reverse movement. Flexible tie straps of this construction are extremely effective in providing adjustable support without causing damage to flexible ducts and wires which easily might be crimped, bent or otherwise damaged by other types of hanger devices.  
           [0004]    Once installed, such tie straps can be removed easily by clipping or cutting the strap. However, for some applications it is desirable to loosen and readjust the strap or to remove it entirely for reuse at a different location. Various attempts have been made to equip tie strap fasteners with release mechanisms. Such release mechanisms are not well configured for ease of operation and require substantial finger strength. They also generally require well developed manual dexterity, since they are not easily grasped. Operartion of such release mechanisms can be facilitated by using a tool. However, it is preferred that the pawl be released manually, without resorting to use of a tool. During use, a tie strap and associated buckle are typically snugged against the duct or wire to be supported. Use of a tool to pry the pawl to a release position involves a risk that the tool will slip and cause damage to the adjacent duct or wire. Moreover, because the cost of flexible tie straps is relatively low, clipping and discarding a tie is the favored procedure where the fastener cannot be released quickly and easily. Collectively, this practice represents a not insubstantial waste.  
           [0005]    There is thus a need for a flexible tie strap with a manual release mechanism that can be easily gripped using one hand to release the strap so that it can be withdrawn from the fastener for adjustment or removal without the use of a tool.  
         SUMMARY OF THE INVENTION  
         [0006]    A flexible tie strap includes an elongated narrow web with a fastener joined at one end. One surface of the web is equipped with a plurality of spaced apart ratchet teeth. The fastener is apertured to receive the free end of the web and includes a tongue with a pawl. The pawl is positioned to engage the web teeth to prevent withdrawal of the web through the fastener. A release tab and a brace or anchor tab are joined to the fastener in spaced relation to each other for flexing the fastener to disengage the pawl from the teeth and release the strap from the fastener. The web of the strap may include a series of spaced apart holes to permit attachment of other devices to the strap.  
           [0007]    Objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.  
           [0008]    The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a fragmentary perspective view of an adjustable flexible tie strap in accordance with the present invention.  
         [0010]    [0010]FIG. 2 is a fragmentary cross sectional view taken along line  2 - 2  of FIG. 1 and showing fastener construction details.  
         [0011]    [0011]FIG. 3 is an enlarged fragmentary cross sectional view taken along line  3 - 3  of FIG. 1 and showing the fastener pawl engaging a ratchet tooth.  
         [0012]    [0012]FIG. 4 is an enlarged fragmentary cross sectional view similar to that depicted in FIG. 3 and showing the release tab in a deflected position, the top wall of the fastener in a flexed position with the pawl in a lifted and disengaged position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.  
         [0014]    A flexible tie strap in accordance with the present invention is generally designated by the reference numeral  10  and is illustrated in FIGS. 1 and 2 to include an elongate flattened web  12  of generally uniform width and having first and second ends  14  and  16 . A fastener or clasp  18  is joined to the first end  14 . The second or free end  16  terminates in a tip  20  which may optionally be rounded off or beveled in order to facilitate insertion into the fastener  18 .  
         [0015]    The web  12  includes on one surface a series of transverse, generally triangular ratchet teeth  22 . The reverse surface of the web  12  may be smooth, or it may have a texture or pattern to facilitate gripping of the bundle to be supported. The teeth  22  are slightly angled toward the fastener  18 , so that each includes a ramp side  24  and a shoulder side  26 . The shoulder side  26  is generally orthogonal to the web  12  and faces the fastener  18 , while the sloped ramp side  24  faces the free end  16 . The web  12  also includes a series of longitudinally spaced apart apertures or holes  28  formed therethrough to enable securing the tie strap  10  to a support structure such as a joist or a beam or to receive hooks or other fasteners to enable suspension of items such as tags from the tie strap. It is foreseen that areas of the web  12  may be formed free of teeth  22  or holes  28  so as to provide a generally flat space for display of embossed, printed or applied advertising indicia (not shown).  
         [0016]    The fastener  18  includes a top wall  30 , bottom wall  32  and a pair of sidewalls  34  and  36  defining a generally rectangular channel or aperture  38  therethrough. The fastener walls  30 ,  32 ,  34  and  36  are sized for passage of the tie strap web  12  through the aperture  38 . The forward portion of the top wall  20  includes a pair of laterally spaced slots or slits  40  and  42  which extend rearwardly to define a flexible tongue portion  44  therebetween. The tongue  44  includes a front margin  46 , a pair of side margins  48  and  50  and a body portion  52 . As best shown in FIGS. 3 and 4, the front  46  margin extends downwardly to form a generally triangular pawl  54 . The pawl  54  includes an angled ramp side  56  facing the strap end  14  and an opposite shoulder side  58  which is collinear with the front margin  46  of the tongue  44  and generally orthogonal to the web  12 . Alternatively, the pawl  54  may be positioned inboard from the leading edge of the tongue  44 .  
         [0017]    As best shown in FIGS. 1 and 2, the fastener top wall  30  includes a movable or release tab  60  and a fixed or anchor tab  62  in opposed spaced relation. The release tab  60  is joined in generally upstanding relation to the end of the tongue  44  and the anchor tab is joined in generally upstanding relation to the opposed end of the fastener  18 . It is foreseen that in certain embodiments the anchor tab  62  may be omitted entirely. The anchor tab  62  may also be joined to the fastener top wall  30  in opposed relation to the release tab  62  at any spaced location on the fastener top wall  30  which is sufficient to permit room for sufficient deflection of the release tab  60  when it is urged toward the anchor tab  62  during use. It is understood that the upstanding tabs  60  and  62  need not necessarily be perpendicular to the fastener top wall  30 , but may be angled toward or away from each other. The tabs  60  and  62  may be equipped with grip enhancers, for example ribs such as swaging, or patterns such as gnurling. While the upstanding margins of the tabs  60  and  62  are depicted in FIGS. 1 and 2 as being rounded off, they may also be constructed in any other suitable configuration. In other embodiments, a pair of opposed, generally horizontal extensions or levers (not shown) may be joined to the upstanding margins of the tabs  60  and  62 .  
         [0018]    The tie strap  10  is preferably constructed of a flexible synthetic resinous material, although any other suitable flexible material such as metal, leather, rubber, fabric or combination of such materials may be employed. The fastener  18  and web  12  are preferably of unitary or fusion welded construction. It is foreseen that when the web  12  is constructed of a material such as a woven textiles, the fastener  18  will be constructed of a flexible shape-retaining material such as synthetic resin, metal or similar material.  
         [0019]    In use, a worker first forms the flexible tie strap  10  into a loop around a pipe, duct or bundle of wires so that the ratchet teeth  22  face outwardly. The user next aligns the strap tip  20  for parallel entry into the fastener  18 , introduces the strap tip  20  into the fastener aperture  38  and urges it through. As the tip  20  emerges through the aperture  38 , the ramp side  56  of the pawl  54  rides over the ramp side  24  of the ratchet teeth  22  adjacent the tip  20 , enabling the web  12  to slide easily through the fastener  18  until the loop is tightened to a selected diameter and the user releases the free end  16  of the strap  10 . The top and bottom walls of the fastener  30  and  32  maintain the pawl  54  in engagement with the ratchet teeth  22  (FIG. 2), so that the pawl shoulder  58  engages the shoulder  26  of an adjacent tooth  22  on the free end  16  side of the tie strap  10 . The tooth shoulder  26  serves as a stop (FIG. 3), preventing withdrawal of the tie strap  10  from the fastener  18 .  
         [0020]    In order to loosen the tie strap  10  for adjustment or removal, a user grasps the release tab  60  and the anchor tab  62 , preferably between the thumb and forefinger of one hand, and urges them together. The anchor tab  62  remains generally fixed in place, although some deflection may occur. The release tab  60  is deflected toward the anchor tab  62  (FIG. 4), which causes the tongue  44  to flex or retract upwardly which in turn shifts the pawl  54  upwardly, disengaging the ratchet tooth shoulder  26  from the pawl shoulder  58  and permitting the web  12  to slide backward through the fastener  18  to release the tie strap  10 . The user may pull on the web  12  to withdraw it through through the fastener  18 , or the user may permit the weight of the tied bundle to push against the tie strap  10  and cause loosening of the loop. Advantageously, the oppositely positioned anchor and release tabs  62  and  60  are easily actuated by a worker using two fingers of one hand, leaving the other hand free for use in withdrawing the web  12  through the fastener  18  or for use in performing other work.  
         [0021]    Those skilled in the art will appreciate that alternatively the free end  16  of one tie strap  10  may be inserted into the fastener aperture  38  of a second tie strap  10  and the free end  16  of the second tie strap  10  similarly inserted into the fastener aperture  38  of the first tie strap  10 . In this manner, two or more tie straps  10  can be intercoupled for use in rigging extremely large ducts or bundles.  
         [0022]    It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.