Abstract:
A method performed and apparatus formed to fabricate an Isofix latch wire arrangement bends an elongated strip about an open profile to form an elongated tubular member, radially penetrating the member with wires across the open profile, and forming enlarged portions on the legs. The enlargements engage opposite sides of the tube to complete abutment of the strip edges to close the profile and join the wires as rivets to the tubular member formed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional Application No. 61/454,905 filed Mar. 21, 2011, the disclosure of which is incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to method and apparatus for reducing time and complexity of producing Isofix child seat restraint anchorages for production original equipment vehicles by combining the formation of the bar with the attachment of latch wires. 
     BACKGROUND 
     The production of motor vehicles comprises multiple vertical manufacturing and assembly steps for many of the assemblies or systems contained within a vehicle. Such vertical processing steps substantially increase the cost of producing the vehicle, especially since each part constructed, and the assembly of the parts manufactured into systems, may be accomplished remotely from the subsequent or final vehicle assembly operations. As a result, the more parts and more assembly required to present the assembly for the next or for final assembly into a motor vehicle under automated production conditions could substantially increase the cost of handling and the complexity of final production. 
     As an example, interior systems such as seating may need to satisfy numerous performance goals. This is particularly true of child seat restraint systems in which a child seat may be restrained by an anchorage system which is assembled to the vehicle chassis or the seating support within the motor vehicle. Not only must such systems restrain a child through various vehicle operating conditions, but such systems must often meet performance and structural standards such as the Federal Motor Vehicle Safety Standards applicable throughout the industry to child seat restraint. 
     Previous attempts to reduce complexity of structures and processing in the development of seating systems are often related to the particular architecture of a seating or a vehicle structure. Changes in one system often do not provide motivations or suggestions that may be incorporated in others or may not provide cost reduction features in other systems. However, one market segment of seat construction utilizes an Isofix bar. Improvements by manufacturing techniques such as those disclosed in U.S. Pat. Nos. 7,131,693 B2, 6,983,526, and 7,484,800 require separate manufacturing, handling and delivery of tubular bars. These bars have been separately sourced from plants and processes outside the control of the suppliers who may attach latch wires to the tube in order to construct an Isofix bar or fabricate its incorporation with the seating mechanisms of various manufacturers and suppliers to the original equipment vehicle manufacturers. For example, other suppliers&#39; improvements in seating anchorages are also subject to the independent manufacture, handling, adaption and delivery of tubing from others in the manufacture of improved child seat anchorages such as those in U.S. Pat. Nos. 7,721,406 and 6,729,687. 
     SUMMARY 
     The present invention overcomes the above mentioned disadvantages by providing a vertically integrated method or apparatus combining tube and rivet assembly. A die formed or roll formed sheet curved to form a tube includes a longitudinal slit that is sealed, at least in part, by rivets. In a preferred embodiment, the rivets are formed by latch wires of the type used for child seat restraints, whose legs may be formed to make collars, and protruding ends that may be enlarged, to abuttingly engage edges of opposed sides of the formed material of the tube extending around a central profile, and securing latch wires to the tube to form latch rings. The rivets can also be inserted through the formed tube in various orientations about the circumference of the tube formed. 
     As a result, the present invention provides formation of the tube to be employed in structures, for example, Isofix child seat restraint anchorages, by incorporating tube fabrication with the assembly of latch wires or other rivet forming structures. As a result, the present invention may reduce substantial manufacturing and material handling operations that can increase the time and cost of supplying assemblies to manufacturers, and as a result, the time and cost of supplying motor vehicles from [[a]] production assembly operations. A latch ring configuration including the formed tube structure may eliminate welding when providing an alternative clamp mechanism that holds the shape and profile of the tube as desired. In addition, the arrangement and alignment of latch wire rivets may serve to prevent separation at the seam or mating zone of the formed tube&#39;s material, and may be adjusted as required to adjust loading requirements upon the assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be more clearly understood by reference to the following detailed description of a preferred embodiment when read in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the views, and in which: 
         FIG. 1  is an elevational view of a child seat restraint anchorage that demonstrates an Isofix [[the]] type of mechanism subject to FMVSS §225 of a previously known type; 
         FIG. 2  is a perspective view of a preformed tube modified to support latch wires in the manner of Isofix latch pairs arranged along the tube of a previously known type; 
         FIG. 3  is a perspective view of a child seat restraint anchorage constructed according to the method and apparatus of the present invention; 
         FIG. 4  is a rotated perspective view of a portion of the assembly shown in  FIG. 3 ; and 
         FIG. 5  is a rotated perspective view of a further completed Isofix arrangement of the method and apparatus according to the present invention, with the environmental structure of the type shown in  FIG. 1  removed for the sake of clarity. 
     
    
    
     DETAILED DESCRIPTION 
     As required, a detailed description of embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     As best shown in the accompanying  FIGS. 3-5 , a riveted, formed tube  28  according to the present invention may be employed where previously known structures have been employed, for example, the child seat restraint anchorage  30  of  FIG. 1  or a known Isofix bar assembly  30  shown in  FIG. 2 .  FIG. 1  displays an environment in which a completed assembly may be employed to meet the structural and performance requirements of Federal Motor Vehicle Safety Standard  225  and others. A vehicle passenger seat  16  includes a seat bottom  20  and a seat back  18 . The anchorage  30  carries the latch wires  26  for positioning of a transverse wire portion at the rear of the seat bottom  20  and toward the front of the seat back  18 . A bracket, stanchion, or other part of the seat assembly joins the anchorage to the vehicle  14 . The child seat  10  is shown carried by the vehicle seat  16  so that a pair of child seat latches  27  are positioned to engage a pair of latch wires  26  in a well-known manner. Nevertheless, it is to be understood that the technology may be employed in other areas without departing from the present invention. 
     As also shown in  FIGS. 3-5  of a preferred embodiment, a cross bar  28 , generally profiled in the form of a tube  23  ( FIG. 2 ) of various cross sectional shapes, may be fabricated as a die formed or roll formed sheet  22  ( FIG. 3 ) is enclosed about an open profile and mated with rivets  25 . In this preferred embodiment, wires used to form the latch wires  26  may form the rivets  25  to fabricate a riveted, formed tube  60  ( FIG. 5 ). The tube  60  may also be provided with latch wires  26  to form an assembly  130  ( FIG. 5 ). 
     As shown in the perspective view of  FIG. 2 , an Isofix bar  30  of known type includes an elongated tube  23 . The tube supports a plurality of latch wires  26 , preferably in pairs such as  70 ,  72 ,  74 , that form latch rings when assembled to the tubular member  23 . Such an assembly may be attached by appropriate means such as brackets  36 ,  37  that secure the assembly within another structure, for example, the seat assembly, support, or the vehicle body structures  46  of a vehicle  14  as generically shown in  FIG. 1 . 
     As represented in  FIGS. 3-5 , one or more rivets  25  hold the formed sheet tube  28  ( FIG. 4 ) together. For improved efficiency, the rivets are preferably formed, at least in part, by legs of the latch wires  26 . Rivets  25  may extend in opposite or angled directions with respect to each other to demonstrate various angular orientations of the rivets, but may be formed by cold-heading or otherwise modifying the wires. When the legs  32  and  34  that extend from a transverse portion  31  of the latch wire  26  are used to form the rivet, they may be aligned in the same direction, but each penetration of the tube  28  may be angularly adjusted as desired. Moreover, oppositely or angularly disposed legs  32  and  34  may be positioned as desired depending on load requirements of the assembly or to maintain its integrity, throughout the pairs of latch wires  26  on the elongated tubular member  60  ( FIG. 5 ) formed from the rolled sheet  28 . 
     The length  50  of the wire ends  38  that protrude through the sides of the formed tube may be limited by the use of collars  40  ( FIG. 3 ), for example, cold headed shoulder  42  ( FIG. 4 ) received against the opposite side of the formed tube. The length  50  of the protruding portion  38  ( FIG. 4 ) may be controlled depending on the width of the gap to be closed at the seam between the edges  52  and  54  of the formed tube as shown in  FIGS. 3 and 4 . The ends  38  of the protruding portion  50  may then be formed as collars  40 , for example, cold-headed as enlarged head  58 , to close the gap of the seam between the abutting ends  52  and  54  of the sheet material forming the tube  28  by roll forming or other shaping fabrication. An enlarged head  58 , however enlarged to create a collar  40 , for example, like cold-headed shoulder  42 , is made with the protruding end  38  of the latch wire  26 , engaging the abutting edges of the formed material  28  together, while fixedly positioning and securing the latch wires  26  to form rings along the formed tube  60  ( FIG. 5 ). 
     While welding may be eliminated, it is not precluded where combinations of the riveted, formed tube  60  can be employed, for example, without the concerns of FMVSS standards, or where vehicle styling or customer pleasing finishes may be applied before assembly that may not be incompatible with welding and previously required welding to be eliminated. Alternatively, welding may be added as a step after assembly, or welding may be used to supplement the integrity of the structure where additional strength or alternative load bearing performance must be provided by the assembly. 
     A method for making a latch ring on an elongated tubular support comprises bending a wire formed with sufficient cross-sectional area to form two legs  32  and  34  extending directionally from a transverse portion  31  spacing the legs from each other. An embodiment may include a process of forming an elongated tubular member  60  by forming or bends that reorient an elongated strip  22  of material to position longitudinal edges  52  and  54  of the strip  22  at adjacent positions about an open profile for binding with rivets  25 . An embodiment may include a structure or process that includes penetrating the latch wire legs  32  and  34  into the strip  22  through the open profile the rolled sheet  28  encloses, and riveting by forming collars  40  at opposed sides of the tubular strip  28  forming the tubular member. An embodiment of a process or structure may include forming enlarged portions  40  on the legs on the opposed sides of the tubular member at a fixed location along the legs  32  and  34  to close any separation between the longitudinal edges  52  and  54 , and enclose the profile, fabricating a tube  60  while securing the latch wire  26  to the tube  60  to form a latch ring. 
     A formed tube  60  with formed wire rivets  25  defines an assembly  130  that comprises a formed sheet  28  presenting longitudinal edges  52  and  54  at adjacent positions about an open profile, and held by a plurality of rivets  25 . Where the wires are provided by latch wire legs  32  and  34 , including a collar portion  40 , such as cold-headed leg portion  42 , a protruding portion  38  of the leg extending across the open profile may be formed as an enlarged head  58 . When the end  38  is cold-headed to form head  58 , the head  58  forces edges  52  and  54  to abut against each other, completing the tube  60  while the head  58  and collar  40  retain the latching wire  26  on the tube  60  while positioning the latching portion  31  for engagement with the latch  27 . The legs are preferably attached in pairs as latch wires  26 , and the latch wires  26  are coupled in pairs, whereby the latch wires  26  and the tube  60  form the closed latch rings in an assembly  130  that may be configured to replace the assembly  30  of  FIG. 2 . 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.