CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of and priority to U.S. Provisional Patent Application No. 60/907,832 filed on Apr. 18, 2007 and U.S. Patent Application No. 60/924,365 filed on May 10, 2007. Both of the aforementioned provisional applications are incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     The present application relates generally to the field of seating systems for use in passenger vehicles. This application relates specifically to the construction of a tube recliner mechanism for use in conjunction with a seat structural system to provide adjustability of the seat-back of a seat system and to provide adequate strength to meet all federal and customer requirements. 
     Seating systems have used many different methods to achieve the combination of adjustability in the form of a reclining seat-back and strength to properly protect the occupant during a vehicle dynamic impact event. Recliner mechanisms have been coupled with the structural components of the seating systems in single sided (i.e., one recliner per occupant) or dual sided (i.e., two recliners per occupant) applications. Recliner mechanisms have used methods of continuous engagement of the internal locking mechanism, such as a planetary gear system or a linear screw mechanism, to achieve these goals. Additionally, recliner mechanisms have used methods of discontinuous engagement of the internal locking mechanism, such as pawl and sector, or rotary recliner mechanisms. These recliner mechanisms have been separate from the other structural components of the seating system and have been connected to the other structural components through the use of bolts, rivets, and welding. It has become commonplace to weld recliner mechanisms to the structural components of the seat system. 
     It would be advantageous if the recliner mechanism was protected from entry of foreign matter and from contact of the other seating components that could interfere with the function of the recliner mechanism. It is also advantageous to have a recliner mechanism with low operation friction and reduced looseness. Looseness in recliner mechanisms lead to complaints in the level of perceived quality as well as noise related issues. It would also be advantageous to join the recliner mechanism to the structural components without the use of welding, bolts or rivets. Welding of recliner mechanisms can cause undesired function by deforming precision components or could cause other problems resulting from weld expulsion during the process. Bolts and rivets add additional mass and cost to the system and their use should be avoided if possible. 
     SUMMARY 
     An exemplary embodiment of a tube recliner mechanism for a vehicle seat having a reclining seat back includes an inner tube extending in a lateral cross vehicle direction and having inboard and outboard ends, an outer tube positioned around the inner tube, and a cylindrical spacer positioned between the inner tube and the outer tube. The relative rotational position of the inner and outer tubes is configured to change via rotation of one of the inner and outer tubes. The spacer, inner tube, and outer tube are all concentrically positioned to thereby reduce friction between the inner and outer tubes during relative movement between the tubes. 
     An exemplary embodiment of a seat system for an occupant of a vehicle that includes a seat-back and a seat-bottom includes a tube recliner mechanism for providing adjustable rotation of the seat-back for the comfort of the occupant. The tube recliner mechanism includes an inner tube extending laterally in a cross vehicle direction and an outer tube positioned around the inner tube. The relative rotational position of the inner and outer tubes is configured to change and the tube recliner mechanism is located adjacent a seat cushion and includes a shroud positioned to cover the tube recliner mechanism to thereby prevent interference between tube recliner and adjacent components of the seat. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary embodiment of a vehicle. 
         FIG. 2  is a perspective view of an exemplary embodiment of a seat system for use in a vehicle. 
         FIG. 3  is a perspective view of an exemplary embodiment of a seat structure including an exemplary recliner mechanism for use in a seat system. 
         FIG. 4  is a front perspective view of an exemplary embodiment of a tube recliner mechanism. 
         FIG. 5  is a rear perspective view of an exemplary embodiment of a tube recliner mechanism. 
         FIG. 6  is a perspective view of an exemplary tube recliner mechanism. 
         FIG. 7  is a partial section view of an exemplary tube recliner mechanism 
         FIG. 8  is a rear view of an exemplary embodiment of a tube recliner mechanism. 
         FIG. 9  is a top view of an exemplary embodiment of a tube recliner mechanism. 
         FIG. 10  is a partial section view illustrating the concentricity of the outer tube, inner tube and spacer. 
         FIG. 11  is a perspective view of an exemplary embodiment of a spacer. 
         FIG. 12  is a perspective view of an exemplary embodiment of a tube recliner mechanism. 
         FIG. 13  is a partial section through the tube recliner mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     The tube recliner mechanism integrates the structural components of the seat system with the mechanism components that are used to rotate the seat-back for comfort adjust or for folding the seat-back flat to provide a flat utility floor. The tube recliner mechanism includes an outer tube pivotally coupled to an inner tube through an internal locking mechanism. The internal locking mechanism includes a plurality of locking pins that rotate when the inner tube rotates, but are able to move inward or outward in a radial direction with respect to the inner tube, in order to engage or disengage a respective aperture in the outer tube. When the pins are moved inward, or towards the center of the inner tube, they become disengaged from their respective aperture in the outer tube, which allows for free rotation between the inner and outer tubes, and thusly provides rotation of the seatback. When the pins move outward, or away from the center of the inner tube, they become engaged with their respective aperture in the outer tube and prevent rotation between the inner and outer tubes, and thusly provide the strength required during a dynamic impact event of the vehicle. The pins may be driven into engagement through the use of springs, such that disengagement of the pin from its respective aperture in the outer tube requires the application of an external force by the occupant. The tube recliner mechanism can be constructed such that the outer tube connects to the back-frame and the inner tube connects to a lower mounting structure, or it may be constructed such that the outer tube connects to a lower mounting structure and the inner tube connects to the back-frame. 
     Operation of a tube recliner system is described in detail in U.S. Patent Application Publication No. 2007/0182228, the disclosure of which is incorporated by reference herein. It is intended that the exemplary embodiments described herein may be used with any suitable tubular recliner system, including but not limited to those disclosed in the aforementioned published patent application. 
     An exemplary embodiment of a tube recliner mechanism includes an outer tube constructed concentric to and around an inner tube, whereby the inner and outer tubes relative rotation through an internal locking mechanism. The outer tube may be connected to the back-frame of the seat system and may be pivotally connected through an internal locking mechanism to the inner tube, which may be connected to a mounting bracket through the process of swaging. The swaging process eliminates the need to weld the inner tube, therefore eliminating the possibility of deforming or warping the precision mechanism components by the addition of heat associated with welding. It is also undesirable to weld tubes because welding processes create expulsion of material (i.e., weld spatter) which may collect inside a tube and create noise and function issues. The swaging process also eliminates the need to use fasteners (e.g., bolts or rivets) to connect the components, which reduces the mass and cost of the seat system. 
     The swaging process is one example of a cold forming process used to create an interference fit between one of the tubes and the seat frame components. According to an exemplary embodiment, the inner tube is connected in an interference fit to the mounting bracket and the outer tube rotates with the seat back. According to another exemplary embodiment, the outer tube is connected to the mounting bracket or side member in an interference fit and the inner tube rotates with the seat back. 
     An exemplary embodiment of a tube recliner mechanism also includes at least one spacer which sits between the inner and outer tubes to provide concentricity and to reduce friction during relative rotation between the tubes. The spacer or outer tube may include an anti-rotation feature which prevents the relative rotation between the spacer and outer tube. An exemplary tube recliner mechanism may further include a shroud which covers the tube recliner mechanism to prevent debris from entering the internal locking mechanism and to prevent other seat system components from contacting the pins of the internal locking mechanism. The outer tube may include protrusions in the form of extruded holes, lanced tabs, or dimples to maintain the proper distance between the shroud and the outer tube. 
     Referring to  FIG. 1 , an exemplary embodiment of a vehicle  10  is illustrated and includes a seat system  15 . An exemplary seat system  15  is illustrated as a front passenger seat system, but may be configured for use as a front driver seat system, or any rear seat system. 
     Referring to  FIG. 2 , an exemplary seat system  15  is illustrated as a fully trimmed single occupant seat system. A fully trimmed seat means that the seat structure has been covered with foam and a material, such as leather or synthetic cloth, to finish the seat, so it is complete and ready for installation into vehicle  10 . According to other exemplary embodiments, a seat system could be constructed for use with multiple occupant seating for use in any seat system within vehicle  10 . 
     Referring to  FIG. 3 , a portion of an exemplary seat system  15  is illustrated without the foam and trim of the seat, such that the structural components which manage the load to which the seat system is subjected (e.g., during a dynamic vehicle impact) are shown. Seat system  15  includes a back-frame  20 , at least one mounting bracket  22 , at least one shroud  24 , and at least one tube recliner mechanism  30 . The seat structure of an exemplary seat system  15  may be constructed with back-frame  20  connected to tube recliner mechanism  30 , and pivotally connected to mounting bracket  22 , through tube recliner mechanism  30 . Mounting bracket  22  is illustrated as connecting to the vehicle floor pan, but may be constructed to connect to a seat structure component such as a seat cushion pan or a track mechanism or other useful seat component. The purpose of shroud  24  is to protect the tube recliner mechanism from being contacted by other components, (e.g., foam being deflected as a result of an occupant sitting in the seat system). Seat system  15  is illustrated as including one tube recliner mechanism  30 , which is constructed including two internal locking mechanisms  31 . An alternative embodiment of tube recliner mechanism  30 , may include one internal locking mechanism  31  and one free pivot on the opposite end of internal locking mechanism  31 . A free pivot means to have two non-locking pivotally connected components. 
     Also referring to  FIG. 3 , an exemplary outer tube  34  may be made from a single section steel and may maintain a uniform diameter and cross sectional thickness throughout the entire length of the single section. 
     According to another exemplary embodiment, the outer tube may be constructed from multiple sections, each having varying mechanical properties (e.g., yield strength), such that the stronger sections are the outer sections which engage internal locking mechanism  31 . This embodiment of the outer tube is more efficient at load carrying or load management, since the higher shear stresses occur as a result of the loading from pins  35 , of internal locking mechanism  31 , which are at the outer ends of the outer tube. Alternatively, the outer tube may join the multiple sections into one tube by a welding process (e.g., laser seam) or other useful process. 
     According to another exemplary embodiment, the outer tube may be constructed from three sections, each having a common outer diameter, but the inner section having a thinner wall thickness than both outer sections. The different sections may be made from the same material or different materials. This embodiment of outer tube is more efficient at load carrying or load management, since the higher shear stresses occur as a result of the loading from pins  35 , of internal locking mechanism  31 , which are at the outer ends of outer tube  34 . Alternatively, the outer tube may join the multiple sections into one tube by a welding process (e.g., laser seam) or other useful process. 
     Referring to  FIG. 4 , an exemplary embodiment of tube recliner mechanism  30  is illustrated and includes an inner tube  32 , an outer tube  34 , a retaining washer  36 , at least one spacer  38  (as shown in  FIGS. 7 and 10 ) and an internal locking mechanism  31 . Outer tube  34  is connected to back-frame  20 , and is pivotally connected to inner tube  32  through internal locking mechanism  31 . Mounting bracket  22  is joined to inner tube  32 , by cold forming the material of the outer end of inner tube  32  so that it forms a mechanical lock over retaining washer  36 , which retains mounting bracket  22  in a fixed lateral and rotational position to inner tube  32 . Other types of joining processes may be utilized to join mounting bracket  22 , such as a welding (e.g., gas metal arc-welding or laser welding), to retaining washer  36  or inner tube  32 . 
     Referring to  FIG. 5 , an exemplary embodiment of tube recliner mechanism  30  is illustrated connected to back-frame  20  and mounting bracket  22 , but shroud  24  is removed for clarity. Outer tube  34  includes a plurality of apertures  37  and includes a plurality of rotationally offset, second apertures  370 , which are engaged by pins (or pawl)  35 , which are illustrated in  FIG. 6 . When pins  35  are engaged in the apertures  37  or  370  of outer tube  34 , tube recliner mechanism  30  prevents rotation between inner tube  32  and outer tube  34 , therefore managing load (e.g., in the event of a dynamic impact by vehicle  10 ). When pins  35  are disengaged from the apertures  37  or  370  of outer tube  34 , tube recliner mechanism  30  allows for rotation between inner tube  32  and outer tube  34 , and the seat-back of the seat system  15  may rotate to provide adjustable comfort or convenience in the form of a fold flat seat-back. 
     Referring to  FIG. 7 , an exemplary embodiment of tube recliner mechanism  30  is illustrated by the partial section view. Inner tube  32  is illustrated after the swaging process which cold forms inner tube  32  to retain laterally retaining washer  36 , which in turn retains mounting bracket  22 . 
     Referring to  FIG. 8 , another exemplary embodiment of tube recliner mechanism  300  is illustrated and includes outer tube  340  and inner tube  32 . Outer tube  340  may be formed with extruded holes  342  extending outward from the circumference of outer tube  340 , which protect the pins of the internal locking mechanism  31  from being contacted by other objects. 
     Referring to  FIG. 9 , another exemplary of tube recliner mechanism  300  is illustrated and includes outer tube  340  and inner tube  32 . Outer tube  340  may be formed with protruded dimples  344  extending outward from the circumference of outer tube  340 , which protect the pins of the internal locking mechanism  31  from being contacted by shroud  24 , which slides over tube recliner mechanism  300 . 
     Referring to  FIG. 10 , an exemplary embodiment of tube recliner mechanism  30  illustrates the concentricity of outer tube  34 , inner tube  32  and spacer  38 . Spacer  38  may be made from a polymeric material (e.g., nylon or polyacetal), preferably through an injection molding process. Spacer  38  may be between the outer tube  34  and inner tube  32 , and acts like a bearing, reducing friction and allowing for easier rotation of outer tube  34  relative to inner tube  32 , as well as reduces noise during relative rotation, and reducing clearance in the system. An exemplary spacer  38  may be constructed of a cylindrical shape with thin wall thickness and may include at least one anti-rotation extrusion  39 , as illustrated in  FIG. 11 . 
     Referring to  FIG. 12 , an exemplary embodiment of tube recliner mechanism  30  is illustrated showing the location of section  13 - 13 , which is shown in  FIG. 13 . Spacer  38  provides a bearing surface to both inner tube  32  and outer tube  34  and spacer  38  includes anti-rotation extrusion  39 , which may engage an aperture in outer tube  34  to prevent rotation between spacer  38  and outer tube  34 . 
     Those reviewing the present disclosure will appreciate that various exemplary embodiments have been described herein. According to an exemplary embodiment, a tube recliner mechanism may include an outer tube constructed concentric to and around an inner tube, whereby the inner and outer tube have relative rotation through an internal locking mechanism. The outer tube may be connected to the back-frame of the seat system and may be pivotally connected through an internal locking mechanism to the inner tube, which may be connected to a mounting bracket through the process of swaging. The swaging process eliminates the need to weld the inner tube, therefore eliminating the possibility of deformation or warping of precision mechanism components by the addition of heat associated with welding. It is also undesirable to weld tubes because welding processes create expulsion of material (i.e., weld spatter) which may collect inside a tube and create noise and function issues. The swaging process also eliminates the need to use fasteners (e.g., bolts or rivets) to connect the components, therefore reducing mass and cost of the seat system. 
     Another exemplary embodiment of a tube recliner mechanism also includes at least one spacer which sits between the inner and outer tubes to provide concentricity and to reduce friction during relative rotation between the tubes. The spacer or outer tube may include an anti-rotation feature which prevents the relative rotation of the two. An exemplary tube recliner mechanism may further include a shroud which covers the tube recliner mechanism to prevent debris from entering the internal locking mechanism and to prevent other seat system components from contacting the pins of the internal locking mechanism. The outer tube may include protrusions in the form of extruded holes, lanced tabs, or dimples to maintain the proper distance between the shroud and the outer tube. 
     An exemplary embodiment of the outer tube is constructed using one section of steel having a uniform thickness. An alternative embodiment of the outer tube may be constructed out of three sections, whereby the two outer sections are constructed out of a higher strength (i.e., a higher mechanical properties) steel than the center section. The three sections are joined (e.g., using a laser welding process), either prior to or after forming into a tube, so that the three are concentric. This offers higher strength to the areas that are subjected to the higher torsional, bending and shear stresses during loading (e.g., during a dynamic vehicle impact) and therefore is more efficient at managing the load and energy exerted on the outer tube. Another alternative embodiment of the outer tube may be constructed out of three sections, whereby the two outer sections are constructed using a thicker material than the center section. The three sections are joined, preferably by a laser welding process, so that the three are concentric. 
     As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. 
     It should be noted that references to relative positions (e.g., “top” and “bottom”) in this description are merely used to identify various elements as are oriented in the FIGURES. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used. 
     For the purpose of this disclosure, the terms “coupled,” “joined,” or other similar terms mean the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature. 
     It is also important to note that the construction and arrangement of the recliner mechanism as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present inventions as expressed in the appended claims.
A tube recliner mechanism for a vehicle seat having a reclining seat back includes an inner tube extending in a lateral cross vehicle direction and having inboard and outboard ends, an outer tube positioned around the inner tube, and a cylindrical spacer positioned between the inner tube and the outer tube. The relative rotational position of the inner and outer tubes is configured to change via rotation of one of the inner and outer tubes. The spacer, inner tube, and outer tube are all concentrically positioned to thereby reduce friction between the inner and outer tubes during relative movement between the tubes.