Abstract:
A shielded strap system for binding loose materials while resisting damage to the materials. The strap system includes a high tensile strength elongated core having an outer protective sleeve. The core can comprise a flat metal strap capable of being stretched to tightly bind the loose materials into a stable bundle. The outer protective sleeve can comprise a coating which partially or completely covers the core. The outer protective sleeve can be shaped to provide extra protection at the core edges for protecting the loose materials against breakage or abrasive wear.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to-systems for retaining a single material and for binding individual materials into a bundle. More particularly, the invention relates to a shielded strap system for binding materials and for protecting the materials against abrasion and other strap induced damage.  
           [0002]    Flat bands or straps bind many different types of materials. Such straps typically comprise an elongated binder which can be wrapped around the loose materials and cinched to contain the materials. Although fibrous and plastic strap binders are used in certain applications, the tensile strength of such straps is often less than the tensile strength of steel straps. Flat metal straps provide significant tensile strength and resist separation and other damage. Although metal wire can bind materials, flat metal bands increase the surface area of the binder in contact with the contained materials. By increasing band surface area contact against the bound materials, puncture damage and deformation of the materials is minimized.  
           [0003]    Representative materials contained by metal straps include spooled cable, bricks and other masonry products, flexible sacks containing powdered or pelleted material, lumber, tubular products, and many other product types. When the strap contacts a flat planar surface of a material or material bundle, little or no damage occurs between the strap and the material. However, a significant amount of product damage can occur when the strap bends around a corner of the material or material bundle. As the metal strap is cinched down to provide a tight containment around the material bundle, the metal strap typically draws the individual materials together and damages the material bundle corner.  
           [0004]    Bundle corner damage is a significant cost in product storage and transportation or deformable and nondeformable products. For deformable loose materials such as lumber, the tightened metal strap compresses the lumber on the corner and permanently deforms the corner edge. For deformable loose materials such as spooled cable having an outer plastic sheath, the metal strap compresses the outer sheath surface and can physically cut the outer plastic sheath surface. If the plastic sheath provides a weathering surface for the cable product, the cut must be repaired before the cable can used. For deformable materials such as a bundle of flexible sacks, the metal strap can cut the sack and release the sack contained material.  
           [0005]    The forces exerted by metal straps on bundled loose materials can also damage relatively nondeformable materials. Cementitious products such as fired bricks are brittle and are susceptible to notch sensitivity failures. If a tightened strap binds the corner of a brick stack, the concentration of strap force at the corner can break the brick in contact with the strap. In addition to damaging the corner brick, such breakage can loosen the strap around the entire bundle if the broken brick pieces are displaced from the original bound position. Once the strap is loosened, failure of the entire bundle can occur during transport.  
           [0006]    In addition to the failures described above, flat metal straps have relatively sharp edges capable of abrading or cutting loose materials in contact with the strap. Painted tubular products such as pipe tubulars are frequently painted with anti-corrosion paints which can become scarred or scratched by contact with metal strap edges. Such damage may require labor intensive repair if the tubulars will be used in long service or high corrosion environments. Additionally, thin walled tubulars such as PVC pipe can be deformed or unnecessarily stressed by the tie-down force applied as the metal bands are cinched down to contain the tubulars.  
           [0007]    Prior art techniques for minimizing metal strap damage typically use localized patches. Such techniques position spacers, cushion pads or “chairs” at strategic locations between the metal strap and the bound materials. Cardboard or plastic spacers are hand positioned between the metal strap and the materials before the metal strap is tightened to cinch the materials. This process requires hand labor and can be ineffective if the cinched metal strap dislocates the spacer during the binding process. Upon such event, extra labor is required to hold the spacer in position as the metal strap is cinched, and the risk of hand injury is increased.  
           [0008]    In addition to these limitations, plastic spacers or chairs are separate from the metal strap and require handling and storage. Because such spacers are often constructed for a particular task, an appropriate spacer may not be available for a particular application. For example, plastic corner protectors used for protecting the corners of loaded brick pallets are not suitable for protecting tubular product bundles or bundles formed with flexible sacks. Similarly, paper spacers used between metal straps and tubular products are not suitable for binding bundles formed with cardboard boxes. The need for various spacers increases the required variety of spacer inventory, slows operations, and encourages the improper use of spacers unsuited for the application.  
           [0009]    A need exists for an improved strap system capable of providing high tensile tie-down forces without damaging the bound materials. The system should be economic to manufacture, should be adaptable to multiple applications, and should resist damage to the bound material.  
         SUMMARY OF THE INVENTION  
         [0010]    The invention provides a shielded strap system for binding a material or a combination of materials. The invention comprises an elongated core resistant to tensile separation and sufficiently flexible to be engagable with the material, a core end capable of being attached to another portion of said core, and a sleeve engaged with said core and positioned between said core and the material.  
           [0011]    In different embodiments of the invention, the core can comprise a metal band or can comprise different configurations or materials. The sleeve can partially or substantially cover the core and can comprise a plurality of discontinuous dimples, a linear ridge, or other shape. The sleeve can have a thicker cross-section near opposing edges of the band and can be partially removable from the core to permit engagement of the core with the material. The sleeve can perform multiple functions such as resisting damage to the material or to the core, and of resisting movement relative movement between the core and the material.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 illustrates the invention engaged with a single material.  
         [0013]    [0013]FIG. 2 illustrates a cross-sectional view for inventive embodiment.  
         [0014]    [0014]FIG. 3 illustrates a band engaged with a material bundle.  
         [0015]    [0015]FIG. 4 illustrates multiple bands binding a bundle of flexible sacks.  
         [0016]    [0016]FIG. 5 illustrates a sheath formed with discontinuous dimples.  
         [0017]    [0017]FIG. 6 illustrates a sheath formed with separate end caps protecting each opposing edge of the band.  
         [0018]    [0018]FIG. 7 illustrates a sheath having a uniform thickness.  
         [0019]    [0019]FIG. 8 illustrates a sheath formed on one surface of a band.  
         [0020]    [0020]FIG. 9 illustrates a sheath is engaged with a portion of the band.  
         [0021]    [0021]FIG. 10 illustrates an embodiment of the invention wherein a sheath initially covers the band and is partially pulled back to expose a free band end. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    The invention relates to a shielded strap system for binding a materials. The invention can be engaged with a single material or can bind multiple materials into a single bundle. The invention is applicable to a wide variety of materials and can bind a material or material bundle while resisting potential damage to the material.  
         [0023]    [0023]FIG. 1 illustrates one embodiment of the invention wherein an elongated core such as band  10  is engaged with a material identified as box  12 . As shown in FIG. 2, band  10  has two generally parallel, flat surfaces identified as first surface  14  and second surface  16 . First surface  14  is proximate to box  12 , and second surface  16  faces away from box  12 . Edges  18  complete outer surface shaping band  10 . Band  10  is formed with a flexible material resistant to tensile separation and provides a structural member for binding box  12 .  
         [0024]    Sheath  20  is illustrated as being engaged with band  10 . Sheath  20  can comprise an organic or inorganic material and can comprise numerous forms. In a preferred embodiment of the invention as shown in FIG. 2, sheath  20  can comprise a plastic or elastomeric material bound or otherwise attached to or engaged with band  10 . Sheath  20  can be heat shrunk to enclose all or a portion of band  10 , and can have a uniform thickness. Alternatively, sheath  20  can have a shape wherein the thickness of sheath  20  is variable about band  10 . As shown in FIG. 2, sheath  20  can have protrusions  22  which extend outwardly from sheath body  24 . Protrusions  22  can be made of a selected material thickness sufficient to contact box  12  and to provide a contact surface against box  12  resistant to movement therebetween. Band end  26  is attachable to another portion of band  10  identified as band section  28 .  
         [0025]    Sheath body  24  and protrusions  22  can be formed with different materials and configurations to accomplish different objectives. One function provided by sheath  20  is to prevent moisture and other compounds from contacting and degrading band  10 . Another function of sheath  20  is to provide surface contact against box  12  which is resistant to slippage or other relative movement. Sheath  20  can have a composition providing a relatively high degree of friction relative to material  12 . Alternatively, sheath  20  can have an adhesive or binding quality relative to material  12  which can be provided by the structure or composition of sheath  20 . Structurally, a softer or “sponge-like” composition of sheath  20  can provide greater gripping capability than a hard, unyielding composition. Sheath  20  can have ridges, serrations, ridges, and other surface discontinuities tending to facilitate contact between sheath  20  and material  12 . In other embodiments of the invention, sheath  20  can be discontinuous over the exterior surface of band  10  to provide a selected pattern or footprint for gripping material  12 .  
         [0026]    A significant function provided by sheath  20  is to resist damage to material  12  as band  10  is cinched tightly into contact with material  12 . When conventional metal bands are cinched tightly around a material or bundle of materials, the metal band and sharp metal edges compress and cut into the bound material. Sheath  20  resists such damage in several ways. First, sheath  20  provides a gripping function against material  12  which lessens the force required to bind material  12 . Consequently, the reduced binding force reduces the compression and localized pressure exerted against material  12 . Secondly, sheath  20  can provide a softer surface against material  12  which automatically adjusts to surface variations in the exterior of material  12 , or in the outer surface of material bundle  30  between individual material bundle components. Additionally, sheath  20  can slide relative to band  10  so that sheath  20  can remain fixed against material  12  as band  10  is moved relative to sheath  20  to tension band  10  against material  12  or material bundle  30 .  
         [0027]    [0027]FIG. 3 illustrates the application of the invention to a plurality of materials collectively identified as material bundle  30 . Material bundle  30  can comprise a variety of individual materials including product filled sacks, bricks and other masonry products, lumber and other wood products, boxes, plastic pipe, As shown in FIG. 3, band  10  and sheath  20  have been positioned about an exterior surface of material bundle  30  and have been cinched tightly against material bundle  30  to bind the individual materials. Connection  32  provides the attachment mechanism for engaging band  10  and sheath  20  with material bundle  30 . Connection  32  can be made with different mechanical or adhesive techniques. If band  10  comprises a structure similar to conventional metal straps, connection  32  can be formed with conventional crimping techniques. In other embodiments of the invention, connection can be mechanically formed with a clasp or other mechanical connector.  
         [0028]    Because band  10  comprises metal in a preferred embodiment of the invention, sheath  20  extends the useful life of band  10  by protecting band  10  from corrosion and notch failures. Consequently, the connection between band free end  26  and the engagement point of band  10  can be accomplished with mechanical connectors of different designs and constructions. Such mechanical connectors can be discarded after one use or can be reusable to permit subsequent use of band  10  and sheath  20  to another material  12  having a similar shape or form. In this manner, the invention reduces material waste by providing a reusable product having extended use.  
         [0029]    [0029]FIG. 4 illustrates an embodiment of the invention wherein material bundle  34  is formed with a plurality of loosely filled sacks which are deformable when compressed. A single band  10  and sheath  20  can be engaged with material bundle  34 , or multiple bands  10  and associated sheaths  20  can be engaged with material bundle as illustrated.  
         [0030]    [0030]FIG. 5 illustrates another embodiment of the invention wherein band  10  is engaged with sheath  36  formed with discontinuous dimples  38 . Dimples  38  can be glued, painted, sprayed or otherwise affixed to or associated with band  10 . FIG. 6 illustrates another embodiment of the invention wherein sheath  40  comprises two end caps engaged with each opposing edge of band  10 . In this embodiment of the invention, the material used for sheath  40  is minimized and the protection provided by sheath  40  against edge abrasion and cutting by the edges of band  10  is maximized. FIG. 7 illustrates another embodiment of the invention wherein sheath  42  has a uniform thickness around the exterior surface of band  10 . FIG. 8 illustrates an embodiment of the invention wherein sheath  44  is positioned on first side  14  of band  10 , and FIG. 9 illustrates an inventive embodiment wherein a section of body  10  is engaged with sheath  46 .  
         [0031]    To use the invention, band  10  can have first end  26  uncovered by sheath  20 . If sheath  20  initially covers first end  26 , sheath  20  can be cut back or otherwise partially removed to expose first end  26  as illustrated in FIG. 10. Subsequently, first end  26  is attached to a middle portion of band  10  identified as band section  28 . If band section  28  is initially covered with sheath  20 , a portion of sheath  20  can be removed to expose band section  28  and to permit direct contact between band first end  26  and band section  28 . After such contact is made, band first end  26  can be attached to band section  28  with conventional attachment techniques known in the art. If desired, a protective coating can be painted, sprayed, or otherwise formed on or attached to the connection between band first end  26  and band section  28  to prevent corrosion or to protect material  12  from abrasive contact with such connection.  
         [0032]    The invention uniquely protects a material from damage as the material is bound for storage or transport. The invention is cost effective to produce, is applicable to multiple and varied applications, and reduces labor cost. The invention can be stored on a spool or reel in a manner similar to the storage techniques for conventional metal straps, and can be dispensed by rotating the storage spool. The invention conserves material and resources by providing a product which can be reused to bind another material, or which can be recycled into the raw components for remanufacture. The durability of the invention supports design and application of reusable clasps which can selectively bind and release band  10  and sheath  20  into engagement with a material bundle.  
         [0033]    Although the invention has been described in terms of certain preferred embodiments, it will be apparent to those of ordinary skill in the art that modifications and improvements can be made to the inventive concepts herein without departing from the scope of the invention. The embodiments shown herein are merely illustrative of the inventive concepts and should not be interpreted as limiting the scope of the invention.