Abstract:
The folding blade terminal of the present invention includes a planar base and elongated terminal blade that are operatively connected through an upward projection fold feature and terminal blade angle hinge feature. In use, the folding blade terminal facilitates point-of-use final terminal forming and integral mechanical pull testing while producing a uniform solder fillet around the perimeter of the terminal base, eliminating the risk of stress points caused by irregular solder fillets. Alternate embodiments of the invention provide a terminal lock disposed at the opposite end of the terminal to prevent the unintentional removal of a box terminal from the terminal blade. Another embodiment of the invention provides a double folding blade terminal. Each of the embodiments of the present invention can be formed to have particular profile heights as required.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This present invention relates to blade-style electrical terminals and more particularly to a folding blade electrical terminal that facilitates final terminal folding and integral mechanical pull testing while providing a uniform solder fillet when mechanically connected to a work surface. 
     2. Description of the Prior Art 
     Electrical terminals must be connected to certain articles of manufacture to allow for the flow of electricity from one medium to a different medium. This is particularly true in instances where the conductive elements are embedded in a non-conductive material, such as glass or dielectric substrate. In, for instance, automotive glass panels having electrical wiring embedded therein for the purpose of defogging the window, electrical terminals must be attached to the glass panels to provide a point of connection for electrical current input and output. 
     Blade-style terminals are frequently employed in applications requiring the supply of electrical current to conductive elements embedded in non-conductive substrates. For example, when providing electrical current to a defrosting grid on an automotive glass panel, conductive paint is applied to the interior glass surface in a pattern that defines the desired electrical circuit. The blade terminals are then soldered to the heating grid. A lead wire is then connected to the blade terminal using an inexpensive industry-standard box-style terminal which is typically crimped or soldered to the end of the lead wire. Once the box terminal is slid over the blade terminal, the electrical connection is completed. One disadvantage of such a box-style terminal is that it can be accidentally disconnected from the blade terminal. Attempts have been made to cover box terminals with plastic housings having a latch to engage the blade terminal in an effort to prevent the accidental disengagement of the box terminals from the blade terminals. The use of such plastic housings, however, increase the overall height of the assembled terminal connection such that it is unacceptable in many industry applications. 
     The blade style of terminal has been developed in several design variations to accommodate specific installations. One such variation employs a U-shaped footprint. These terminals have a base having a pair of elongated symmetrical feet that extend outwardly from a center section in a parallel fashion to form a U-shape. The blade typically extends upwardly from the center section at a desired angle relative to the base. This design is further modified through the use of an optional reinforcing “rib” that is formed in the center of the terminal blade, extending upwardly along the lower portion of the blade. The rib is used to facilitate mechanical pull testing of the terminal&#39;s connection to the work surface without changing the blade&#39;s angle. The disadvantage in using the rib feature is that the terminal blade cannot be bent after the soldering and pull testing steps for final assembly without fracturing the soldered connection. Without the reinforcing rib detail, the terminal blade can be pressed downward to an appropriate angle for final assembly. However, without the rib detail, the terminal cannot be pull-tested to verify the strength of the solder joint without the terminal blade bending and causing the solder joint to fracture. 
     Another variation of the blade terminal is provided with a narrow “inline” footprint, which is formed by two individual solder pads at the opposite ends of the terminal that are connected to one another by a raised bridge portion. The raised bridge and individual solder pads accommodate the differential of thermal expansion between the base material and the terminal, which would typically weaken the solder joint. However, the inline terminal cannot be pull-tested to verify the strength of the solder joint without bending the bridge portion and causing the solder joint to fracture. 
     Another disadvantage with either the U-shaped or inline designs is that the pre-clad solder material on their lower surfaces reflows when the terminal is soldered. The solder then typically cools, having formed an irregular solder fillet between the terminal base and the upward projection structure such as the terminal blade or bridge portion. The irregular fillet creates concentrated stress points on the work surface, which is unacceptable in the industry. 
     Accordingly, what is needed is a blade terminal that facilitates point-of-use final terminal forming and integral mechanical pull testing while having a uniform solder fillet around the base of the terminal. 
     SUMMARY OF THE INVENTION 
     The folding blade electrical terminal of the present invention is provided with a uniform planar base that, when soldered to a working surface, creates a uniform solder fillet around the base&#39;s perimeter. A terminal blade is operatively connected to one end of the base through an upward projection fold feature and a terminal blade angle hinge feature. These features allow for point-of-use final terminal forming, variable blade angle positioning for assembly, and final assembly angle-setting once the terminal is soldered to the work surface. The terminal blade is formed to receive an industry-standard box-style terminal to complete an electrical connection. 
     In an alternate embodiment, the folding blade electrical terminal of the present invention is further provided with an interlock that extends upwardly from the base at the opposite end from the terminal blade. Once the box terminal has been secured to the terminal blade and the terminal blade has been folded adjacent the base, the interlock prevents the box terminal from unintentionally sliding off the terminal blade. Other embodiments of the present invention include an optional second terminal blade, and embodiments having varied profile heights. 
     It is therefore a principal object of the invention to provide a blade terminal that facilitates point-of-use final forming and integral mechanical pull testing while providing a uniform solder fillet around the terminal&#39;s footprint. 
     Yet another object of the invention is to provide a blade terminal that allows for variable blade angles for assembly. 
     Still another object of the present invention is to provide a blade terminal that allows for final assembly angle-setting after soldering. 
     Yet another object of the present invention is to provide a folding blade terminal having an interlock to prevent the unintentional removal of a box terminal that is secured to the terminal blade. 
     Still another object of the invention is to provide a folding blade terminal that can be formed with a variable profile height. 
     Yet another object of the present invention is to provide a folding blade terminal that is formed to receive a low profile interlocking cover piece to prevent the unintentional disengagement of a lead wire from the interlock. 
     These and other objects will be apparent to those skilled in the art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a prior art blade terminal having a U-shaped footprint after the same has been soldered to a work surface; 
     FIG. 2 is a perspective view of a prior art inline blade terminal after the same has been soldered to a work surface; 
     FIG. 3 is a perspective view of the folding blade terminal of the present invention; 
     FIG. 4 is a perspective view of the folding blade terminal of the present invention illustrating one manner in which the blade of the terminal receives a prior art box terminal; 
     FIG. 5 is a side elevation view of the folding blade terminal of the present invention in a final assembly angle-setting connected to a prior art box terminal; 
     FIG. 6 is a perspective view of an alternate embodiment of the folding blade terminal of the present invention; 
     FIG. 7 is a side elevation view of the folding blade terminal of FIG. 6, shown coupled with a prior art box terminal; 
     FIG. 8 is a perspective view of an alternate embodiment of the folding blade terminal of FIG. 3; 
     FIG. 9 is a perspective view of an alternate embodiment of the folding blade terminal of FIG. 6 having a large bend radius and increased profile height; 
     FIG. 10 is a side elevation view of the folding blade terminal of FIG. 9 in a final assembly angle-setting; 
     FIG. 11 is a bottom perspective view of the folding blade terminal of FIG. 6; and 
     FIG. 12 is a front perspective view of an alternate embodiment of the folding blade terminal of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 depicts a prior art U-shaped blade terminal  500  having a base  502  comprising a center section  504  and a pair of elongated feet  506  and  508  extending outward from center exterior section  504 . A pre-clad solder layer (not shown) is applied to the lower surface of base  502  prior to forming the U-shaped blade terminal  500 . The terminal blade  510  is formed by displacing the material between the symmetrical feet  506  and  508 . Accordingly, the terminal blade  510  has a portion of the pre-clad solder layer, which was applied to the base  502 , disposed along part of its lower surface. In different embodiments, prior art U-shaped terminal  500  may have a reinforcing rib detail (not shown) adjacent the center exterior section  504  and the lower portion of the upper surface of terminal blade  510  to prevent the terminal blade  510  from being deflected. 
     During a soldering operation, the pre-clad solder layer on the bottom of base  502  and terminal blade  510  flows to the work surface on which the terminal is being connected. This forms a solder fillet  512  adjacent the center interior section  504  between the terminal blade  510  and the symmetrical feet  506  and  508 . FIG. 1 illustrates that the solder fillet  512  will typically be much larger than the solder fillet  514  that is formed adjacent the perimeter of the remaining portions of base  502 . The lack of uniformity between the solder fillets creates an unacceptable stress point on the work surface, which increases the likelihood of a fracture in the work surface beneath the point of connection. 
     If the terminal blade  510  is deflected after soldering during a pull strength test or a final assembly positioning of a box terminal, the higher solder fillet  512  will fracture where it is soldered to the work surface. This fracture will be visible from the exterior of glass work surfaces, which is not acceptable in the industry. 
     FIG. 2 depicts a prior art inline blade terminal  600  having two base pads  602  and  604 , positioned at opposite ends of a raised bridge section  606 . A pre-clad solder layer (not shown) is applied to the bottom surface of base pads  602  and  604  and across the bottom surface of the raised bridge section  606  prior to forming the terminal. The terminal blade  608  is formed by displacing the material adjacent to the solder pads  602  and  604  and raised bridge section  606  in an upward manner. The terminal blade  608  is hingedly coupled to the raised bridge section  606  by hinge feature  610 . During a soldering operation, the pre-clad solder layer on the bottom surface of raised bridge section  606  flows from the terminal to the work surface. A solder fillet  612  is formed adjacent the bridge section  606  and the two solder base pads  602  and  604 . The solder fillet  612  is much larger than the solder fillets  614 , which extend along the remainder of the outside perimeter of the two base pads  602  and  604 , as shown in FIG.  2 . The lack of uniformity between the solder fillets creates undesirable stress points on the work surface that increase the likelihood of fractures in the solder joint and the work surface. 
     The terminal blade  608  cannot be used for pull strength testing due to the flexible nature of the hinge feature  610 . Rather, the raised bridge section  606  must be used during such testing. The disadvantage in using the raised bridge section  606  is that it becomes a fulcrum when used for pull testing between the two solder pads  602  and  604 , causing a fracture where solder pads  602  and  604  are soldered to the work surface. This fracture is visible from the exterior of glass work surfaces and is not acceptable in the industry. 
     FIGS. 3 through 5 depict the folding blade terminal  100  of the present invention. Terminal  100  is provided with a planar base  102 , having a bottom surface  104  with multiple projections  106  extending downwardly a predetermined distance from bottom surface  104 . Projections  106  define a minimum thickness that the solder joint will achieve during the soldering process in a manner similar to that taught in U.S. Pat. No. 4,246,467. A pre-clad solder layer  107  is applied to the bottom surface  104 . However, the terminal  100  can also be secured to work surfaces using a wire feed solder system or materials other than solder, such as various types of conductive adhesive. 
     FIG. 3 depicts the base  102  of the terminal  100  as having a generally square or rectangular shape. In an alternate embodiment, shown in FIG. 12, the terminal blade  400  is shown with a base  402  having a circular or generally rounded shape. When it is necessary, a base having a rounded shape can be used to increase the amount of electrical current dissipated by the terminal. While the U-shaped footprint of terminal  500  provides a large peripheral edge that will dissipate an increased amount of electrical current, the rounded base  402  will dissipate an increased amount of electrical current without forming hot spots adjacent its base  402 . The U-shape of the base  502  will form a hot spot between the elongated feet  506  and  508 , which is undesirable. 
     The base  402  has been further modified with an optional opening  403  formed therethrough. The opening  403  allows the base  402  to exert less stress on the work surface it is connected to during moments of thermal expansion where a work surface such as glass will have a different coefficient of thermal expansion than the base  402 . The opening  403  allows for the thermal expansion of base  402  regardless of the difference in the coefficient of thermal expansion between the base  402  and the work surface. Since the base  402  is allowed to expand and contract more freely, less stress is placed on the connection and the work surface. Additionally, the opening  403  creates two identical parallel electrical currents for electrical resistance soldering of the terminal  400 . The parallel circuits are created when a pair of soldering electrodes contact the upper surface  405  of the base  402  180 degrees from each other, relative to the center line of opening  403 . 
     In FIGS. 3 through 5, the rearward end of the base  102  is provided with a terminal blade  108  having a pair symmetrical indentations  110  and  112  that form an upward projection fold feature  114  and a terminal blade angle hinge feature  116 . Preferably, the terminal blade angle hinge feature  116  is accompanied by an opening  117 , which is positioned intermediate the indentations  110  and  112  in terminal blade  108 . By reducing the amount of material between the indentations  110  and  112  at a select location along the terminal blade  108 , the terminal blade angle hinge can be more accurately located to provide a desired terminal profile height. While the material between the indentations  110  and  112  can be reduced by increasing the size of the indentations  110  and  112  or providing the opening  117  it is also contemplated that the thickness of the material at that point could be reduced. For example, crimping, compressing, or removing portions of the material along either or both surfaces of the blade  108  will create a reduced thickness. This reduced thickness will form an upward projection fold feature  114 . 
     Rib detail  128  can be optionally formed in terminal  100  along the projection fold feature  114 , extending from the base  102  to the terminal blade  108 . The rib detail can be formed to work in conjunction with the terminal blade angle hinge feature  116  and opening  117  to locate a terminal blade angle hinge and form a larger bend radius and profile height. 
     When a pre-clad solder layer is applied to the bottom surface  104 , it is preferred that terminal blade  108  be kept free of solder to help prevent the formation of uneven solder fillets. Terminal blade  108  is shaped to have chamfer features  118  formed in its outer edge, which facilitate its insertion into a box terminal  700 . Adjacent to the symmetrical indentations  110  and  112  is a pair of symmetrical projection tabs  120  and  122  that extend outwardly from the blade angle hinge feature  116 , providing a positive stop for box terminal  700  as shown in FIG. 4. A hole  124  in the center of terminal blade  108  engages a projection  702  on box terminal  700  to secure it in place after it has been inserted onto terminal blade  108 . 
     As the terminal  100  is soldered to the work surface, the solder will flow between the bottom surface  104  of the base  102  and the work surface. A uniform solder fillet  126  will form along the perimeter of the base  102 . No irregular solder fillets will form along the structure of base  102 , thus eliminating the potential for stress points along the connection point. After the soldering phase, the strength of the solder joint can be subjected to a pull strength test, which can be achieved by symmetrically gripping tabs  120  and  122  on terminal blade  108  and applying the appropriate amount of upward pulling force. Thereafter, terminal blade  108  can be bent along the blade angle hinge feature  116  to facilitate its insertion into a box terminal  700 . Finally, the terminal blade  108  is bent into its final assembly position adjacent the base  102 , as shown in FIG.  5 . 
     In an alternate embodiment, shown in FIGS. 6,  7 , and  9  through  11 , a folding blade electrical terminal  200  is provided with a planar base  202 , having a bottom surface  204  with a plurality of projections  206  extending downwardly therefrom. As with projections  106 , discussed previously, projections  206  define a minimum thickness that the solder joint will achieve during the soldering process in a manner similar to that taught in U.S. Pat. No. 4,246,467. A pre-clad solder layer  207  is applied to the bottom surface  204 . However, the terminal  200  can also be secured to work surfaces using a wire feed solder system or materials other than solder, such as various types of conductive adhesive. 
     The rearward end of the base  202  is provided with a terminal blade  208  which is similar to terminal blade  108  in structure and function. Terminal blade  208  is provided with a pair of indentations  210  and  212  that form upward projection fold feature  214  and a terminal blade angle hinge feature  216 . The terminal blade angle hinge feature  216  is optionally provided with an opening  217  to more easily and accurately locate the terminal blade angle hinge in terminal blade  208 . Rib detail  228  can be optionally formed in terminal  200  along the projection fold feature  214 , extending from the base  202  to the terminal blade  208 . The rib detail  228  can be formed to work in conjunction with the terminal blade angle feature  216  and opening  217  to locate a terminal blade angle hinge and form a larger bend radius and profile height. 
     When a pre-clad solder layer is applied to the bottom surface  204 , it is preferred that terminal blade  208  be kept free of solder to help prevent the formation of uneven solder fillets. Chamfer features  218  are formed into the leading edge of terminal blade  208 . Projection tabs  220  and  222  extend outwardly from the blade angle hinge feature  216  to provide a positive stop for box terminal  700 . An opening  224 , formed in the center of terminal blade  108 , engages projection  702  on the box terminal  700  to secure it in place. 
     The forward end of base  202  is provided with an interlock  230 , which extends upwardly therefrom. The interlock  230  is provided with a pair of symmetrical indentations  232  and  234  that form an upward projection fold feature  236  and tabs  238  and  240 . A cutout  242  in interlock  230  provides clearance for the box terminal  700  after terminal blade  208  has been secured in its final assembly angle setting. In this position, tabs  238  and  240  engage the lower end of box terminal  700  and prevent it from being removed from terminal blade  208 . Opposing inner tab portions  244  and  246  of cutout  242  are formed to engage the round crimp feature  704  that secures lead wire  706  to box terminal  700 . 
     As the terminal  200  is soldered to the work surface, the solder will flow between the lower surface  204  of base  202  and the work surface in a manner similar to that exhibited with terminal  100 . As the solder cools, a uniform solder fillet  226  will be formed along the perimeter of the base  202 . As with terminal  100 , no structure is provided adjacent the perimeter of base  202 , along which solder will flow from and form a solder fillet larger than solder fillet  226 . Accordingly, the potential for the formation of a stress point at the solder joint is eliminated due to the lack of irregular solder fillets. 
     Once the terminal  200  has been soldered to the work surface, the strength of the solder joint can be tested. A pull strength test is applied to terminal  200  by uniformly and symmetrically gripping tabs  238  and  240  on interlock  230  and tabs  220  and  222  on terminal blade  208  and applying an appropriate amount of upward force. The ability to uniformly and symmetrically grip the terminal  200  by tabs  238 ,  240 ,  220  and  222  minimizes the possible deflection of base  202  and fracturing of the solder joint. 
     After the soldering and pull test phases, the terminal blade  208  can be deflected downwardly toward base  202  via the blade angle hinge feature  216  to facilitate insertion of the terminal blade  208  into box terminal  700 . The terminal blade  208  and box terminal  700  are then bent into their final assembly position adjacent base  202 , with the box terminal  700  being retained via the interlock tab features  238  and  240 . Opposing inner tabs  244  and  246  of cutout  242  engage the crimp feature  704  of box terminal  700  which, in combination of the aforementioned structural features, prevents the terminal blade  208  from raising upward and further prevents box terminal  700  from sliding off terminal blade  208 . 
     FIGS. 6 and 7 depict an insulating cover  800  that is secured around terminal  200  and box terminal  700  in their final assembly setting. The insulating cover  800  is retained by tabs  238  and  240  on interlock  230  and an opposing set of internal gripper details  802  and  804 . Features  806  and  808  engage the blade gripping features  708  and  710  on the box terminal  700 . The insulating cover  800  retains the terminal blade  208  in its assembled position and further relieves stress placed on lead wire  706 . 
     In another embodiment, shown in FIG. 8, a dual folding blade terminal  300  is provided with a planar base  302  having a bottom surface  304  with a plurality of projections  306  extending downwardly a particular distance from the bottom surface  304  to define a minimum thickness that the solder joint will achieve during the soldering process in a manner similar to that taught in U.S. Pat. No. 4,246,467. A pre-clad solder layer  307  is applied to the bottom surface  304 . However, the terminal  300  can also be secured to work surfaces using a wire feed solder system or materials other than solder, such as various types of conductive adhesive. The rearward end of base  302  is provided with a terminal blade  308  that is similar in structure and function to terminal blades  108  and  208 . Terminal blade  308  is comprised of a pair of symmetrical indentations  310  and  312  that provide an upward projection fold feature  314  and a terminal blade angle hinge feature  316 . 
     The terminal blade angle hinge feature  316  is optionally accompanied by an opening  317  to more easily and accurately locate the terminal blade angle hinge in terminal blade  308 . As with terminals  100  and  200 , terminal  300  can be selectively provided with a reinforcing rib detail  328  that extends upwardly from base  302  along projection fold feature  314  and connecting to the lower portion of terminal blade  308 . Rib detail  328  is formed into terminal  300  to work alone or in conjunction with terminal blade angle hinge feature  316  and opening  317  to locate a terminal blade angle hinge and form a larger bend radius and profile height. 
     Chamfer features  318  are formed into the leading edge of terminal blade  308  to facilitate its insertion into box terminal  700 . A pair of symmetrical projection tabs  320  and  322  extend outwardly from the blade angle hinge feature  316 , providing a positive stop for box terminal  700 . An opening  324  is formed in the center of terminal blade  308  to engage projection  702  on box terminal  700  to secure it in place. 
     The forward end of base  302  is provided with a terminal blade  308 ′ which is similar to terminal blade  308  in structure and function. Terminal blade  308 ′ is shown in FIG. 8 having a pair of symmetrical indentations  310 ′ and  312 ′ that form upward projection fold feature  314 ′ and a terminal blade angle hinge feature  116 ′. Opening  317 ′ is optionally provided to more accurately and easily locate the terminal blade angle hinge in terminal blade  308 ′. The upper edge of terminal blade  308 ′ is provided with chamfer features  318 ′ to receive a second box terminal  700 ′. Symmetrical projection tabs  320 ′ and  322 ′ provide a positive stop for the second box terminal  700 ′, and opening  324 ′ is provided to engage a projection  702 ′ on the second box terminal  700 ′. 
     When a pre-clad solder layer is applied to the bottom surface  304 , it is preferred that the terminal blades  308  and  308 ′ be kept free of solder to help prevent the formation of uneven solder fillets. As terminal blade  300  is soldered to a work surface, the aforedescribed structure will function similarly to that found in terminals  100  and  200  in that the solder will flow between the lower surface  304  of base  302  and the work surface, forming a uniform solder fillet around the perimeter of base  302 . The uniform solder fillet eliminates the risk of stress points caused by irregular solder fillets found in the prior art. After the soldering phase, the strength of the newly tested solder joint can be subjected to a pull strength test by uniformly and symmetrically gripping tab features  320  and  322  on terminal blade  308  and tabs  320 ′ and  322 ′ on terminal blade  308 ′ and applying an upward pulling force. The uniform manner in which forces are exerted on the solder joint minimizes the deflection of base  802 , reducing the risk of solder joint fractures. 
     After the solder and pull test phases, the terminal blades  308  and  308 ′ can be deflected downwardly via the blade angle hinge features  316  and  316 ′ to facilitate their insertion into box terminals. The terminal blades  316  and  316 ′ are then bent into their final assembly positions. Depending on the application, it is contemplated that the terminal blades  308  and  308 ′ may both be bent away from base  302 , both be left extending perpendicularly from base  302 , or one positioned adjacent base  304  and the other either positioned perpendicular to or away from base  302 . 
     The insulating cover  800 , shown in FIGS. 6 and 7, can be easily secured around terminal  300  and box terminal  700  in a final assembly setting. Features  806  and  808  engage the blade gripping features  708  and  710  on the box terminal  700 . Accordingly, the insulating cover  800  can be used to cover either the terminal blade  308  or the terminal blade  308 ′. A second insulating cover  800  can be used when an application requires separate covering of both terminal blades. The insulating cover  800  can also be enlarged to simultaneously cover both terminal blades. 
     Each of folding blade terminals  100 ,  200 ,  300  and  400  will have a particular profile height, measured from the work surface to the highest point of the terminal blade when it is set in its final assembly angle setting. The height of the profile achieved by each terminal is determined in part by the positioning of the terminal blade angle hinge opening  117 ,  217 ,  317  and  417  along their respective terminal blades a specified distance from upward projection fold features  114 ,  214 ,  314  and  414 , respectively. For example, FIG. 3 illustrates folding blade terminal  100 , having a terminal blade angle hinge opening  117  that is positioned a short distance “X 1 ” from upward projection fold feature  114 . This position provides for a small bend radius and shortened profile height “A”, shown in FIG.  5 . Alternatively, FIG. 9 depicts a folding blade terminal  200  having terminal blade angle opening  217  that is formed in terminal blade  208  a distance “X 2 ′” from upward projection fold feature  214 , which is greater than distance “X 1 ” by a chosen distance ΔX. This change in separation distance between the upward projection fold feature and the terminal blade angle hinge feature translates into an increased profile height “B”, shown in FIG. 10, which is greater than profile height “A” by a distance of ΔX. 
     Where an increase in profile height is desired, a rib detail  228  can be selectively formed to extend from the base  202 , along upward projection fold feature  214 , to terminal blade  208 , as shown in FIG.  9 . The rib detail  228  will resist deflection of terminal blade  208  below the point it connects with terminal blade  208 . Accordingly, the greater the profile height desired, the higher the rib detail  228  should connect with terminal blade  208 . Rib detail can be used alone or in conjunction with the terminal blade angle hinge opening  217 , depending on the desired application. 
     Where a moderate profile height is desired, no terminal blade angle hinge feature opening  217  or rib detail  228  should be provided. Leaving only the upward fold feature  214  intermediate the base  202  and the terminal blade  208 , the lower portion of the terminal blade  208  adjacent the upward fold feature  214  will bend downwardly toward base  202  in a tight radius, determined only by the flexibility of the material used to form the terminal. 
     In the drawings and in the specification, there have been set forth preferred embodiments of the invention; and although specified items are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and proportion of parts, as well as substitute of equivalents, are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims. 
     Thus, it can be seen that the invention accomplishes at least all of its stated objectives.