Seat rail assembly

Abstract

To provide a seat rail assembly that supports a position of a seat, and enables easy operation of the seat without rattling and undesirable resistance.SOLUTION: A seat rail assembly comprises an upper rail 104 to which a seat is attached, and a lower rail 102 which is attached to a vehicle floor. The upper rail 104 is provided slidably in the lower rail 102, incorporates an engagement assembly and a dual wedge engagement assembly, and ensures continuous contact between the lower rail 102 and the upper rail 104. Further, a gear box, which is so configured as to prevent rattling since the upper rail 104 is moved with respect to the lower rail 102, may be provided on the upper rail 104.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 107,811, filed October 30, 2020, U.S. Provisional Patent Application No. 63 / 107,822, filed October 30, 2020, and U.S. Provisional Patent Application No. 63 / 107,840, filed October 30, 2020. The entire disclosures of all of the above applications are incorporated herein by reference. [Background technology]

[0002] Seat rail assemblies are incorporated into vehicles to movably mount passenger seats to the vehicle floor. Seat rail assemblies typically include a lower rail attached to the vehicle floor and an upper rail to which the passenger seat is attached. The upper rail is slidably coupled to the lower rail so that the passenger seat can slide fore and aft. However, as the vehicle moves, vibrations are transmitted to the seat rail assembly, which can cause rattle between the lower and upper rails. Furthermore, during the manufacture of the lower and upper rails, height variations and irregularities can occur along the length of the rails, especially when long rails are manufactured. When such height variations and irregularities exist, existing assemblies have difficulty maintaining consistent contact between the lower and upper rails, which can also cause rattle. Such rattle is undesirable and can even result in unacceptable performance.

[0003] To reduce such rattle, existing seat rail assemblies sometimes incorporate a slider assembly that connects an upper rail to a lower rail. However, existing slider assemblies may provide too much, too little, or uneven sliding resistance when sliding forward and / or rearward. Existing slider assemblies may not maintain constant contact between the lower rail and the upper rail to achieve adequate sliding resistance, which can result in undesirable rattle. Therefore, there is a need for an improved seat slide assembly. Summary of the Invention [Means for solving the problem]

[0004] According to the present disclosure, there is provided a seat rail assembly for mounting a vehicle seat. In one embodiment, the seat rail assembly of the present disclosure includes a lower rail configured to be mounted to a vehicle floor, the lower rail defining a sliding space; an upper rail configured to support at least one vehicle seat mounted thereon, at least a portion of the upper rail disposed within the sliding space of the lower rail and slidable relative to the lower rail in a first direction or a second direction opposite the first direction; and an engagement assembly disposed within the sliding space of the lower rail, the engagement assembly adapted to move in response to movement of the upper rail relative to the lower rail. and an engagement assembly including a lower engagement member and an upper engagement member configured to move independently of each other in response to a sliding movement of the lower engagement member, the lower engagement member being slidably mounted on the upper rail and the upper engagement member being slidably mounted on the lower engagement member between a first position and a second position, wherein the lower engagement member is biased in a first direction and the upper engagement member is biased in a second direction toward the first position, and when the upper rail slides in the first direction or the second direction relative to the lower rail, the upper engagement member maintains contact with the lower rail and the lower engagement member maintains contact with the upper rail.

[0005] In a further embodiment, the surface of the upper engagement member maintains contact with the surface of the lower rail, and the surface of the lower engagement member maintains contact with the surface of the upper rail. In a further embodiment, the surface of the upper rail is an inclined surface, and the lower engagement member is slidably disposed on the inclined surface. In another embodiment, the surface of the upper engagement member is a side surface of the upper engagement member, and the surface of the lower engagement member is a side surface of the lower engagement member. In another embodiment, the surface of the upper engagement member is an upper surface of the upper engagement member, and the surface of the lower engagement member is a lower surface of the lower engagement member. In another embodiment, the surface of the lower rail is an inner surface of the lower rail, and the surface of the upper rail is an outer surface of the upper rail. In another embodiment, the surface of the lower rail is an outer surface of the lower rail, and the surface of the upper rail is an inner surface of the upper rail. In a further embodiment, the upper surface of the upper engagement member maintains contact with the inner surface of the lower rail, and the lower surface of the lower engagement member maintains contact with the surface of the upper rail. In some embodiments, a track is formed on the lower engagement member, and the upper engagement member is configured to engage the track when sliding on the lower engagement member. In further embodiments, the track has a slope with an opposite sign to the slope of the upper rail's inclined surface. In further embodiments, the slope of the track and the slope of the upper rail's inclined surface are the same magnitude. In some embodiments, the height of the engagement assembly, measured between the upper surface of the upper engagement member and the lower surface of the lower engagement member, is greatest when the upper engagement member is in the first position. In some embodiments, the lower engagement member is biased in a first direction by a tension spring. In further embodiments, a first end of the tension spring is attached to the upper rail and a second end of the tension spring is attached to the lower engagement member. In some embodiments, the upper engagement member is biased in a second direction by a torsion spring. In further embodiments, a first end of the torsion spring is attached to the upper engagement member and a second end of the torsion spring is attached to the lower engagement member. In further embodiments, the torsion spring prevents the upper engagement member from moving beyond the second position on the lower engagement member. In some embodiments, the lower engagement member includes a stop that prevents the upper engagement member from moving beyond the second position on the lower engagement member.In some embodiments, the lower engagement member includes a stop that prevents the upper engagement member from moving beyond a first position on the lower engagement member.

[0006] In some embodiments, the upper rail has a first end and a second end opposite the first end, the engagement assembly includes a first engagement assembly and a second engagement assembly, the first engagement assembly is disposed within the sliding space of the lower rail proximate the first end of the upper rail, the second engagement assembly is disposed within the sliding space of the lower rail proximate the second end of the upper rail, a lower engagement member of the first engagement assembly maintains contact with a first surface of the upper rail, and a lower engagement member of the second engagement assembly maintains contact with a second surface of the upper rail. In further embodiments, the first surface of the upper rail is a first inclined surface, the second surface of the upper rail is a second inclined surface, the lower engagement member of the first engagement assembly is slidably disposed on the first inclined surface of the upper rail, and the lower engagement member of the second engagement assembly is slidably disposed on the second inclined surface of the upper rail. In some embodiments, the first slope has a slope of the opposite sign to the slope of the second slope, and in further embodiments, the slopes of the first and second slopes are the same magnitude.

[0007] In some embodiments, the seat rail assembly further comprises a lateral displacement control mechanism for controlling relative lateral displacement of the upper rail and the lower rail. In some embodiments, the lateral displacement control mechanism is supported by the upper rail. In further embodiments, the lateral displacement control mechanism maintains contact with both the upper rail and the lower rail. In some embodiments, the lateral displacement control mechanism includes one or more ribs that abut the lower rail.

[0008] Also according to the present disclosure, there is provided a rail assembly including: a first rail configured to be mounted on a first structure, the first rail defining a sliding space; a second rail configured to support a second structure mounted thereon and to be movable relative to the first structure, at least a portion of the second rail disposed within the sliding space of the first rail and slidable relative to the first rail in a first direction or a second direction opposite the first direction; and an engagement assembly disposed between the first rail and the second rail, the engagement assembly including a first surface and a second surface configured to move independently of each other in response to movement of the second rail relative to the first rail, the first surface being configured to move relative to the second rail. and an engagement assembly slidably mounted on the sliding surface of the rail of the first rail, and a second surface slidably mounted on the first surface between a first position and a second position, wherein the first surface of the engagement assembly is biased in a first direction and the second surface of the engagement assembly is biased in a second direction toward the first position, wherein as the second rail slides relative to the first rail, the second surface of the engagement assembly maintains contact with an inner surface of the first rail and the first surface of the engagement assembly maintains contact with the sliding surface of the second rail, and a height of the engagement assembly measured between the second surface of the engagement assembly and the first surface of the engagement assembly is greatest when the second surface of the engagement assembly is in the first position. In some embodiments, the sliding surface of the second rail is an inclined surface, and the first surface of the engagement assembly is slidably mounted on the inclined surface. In some embodiments, the engagement assembly further includes a first engagement member and a second engagement member, and the first surface of the engagement assembly is a surface of the first engagement member and the second surface of the engagement assembly is a surface of the second engagement member.

[0009] The present disclosure also provides a seat rail assembly for mounting a vehicle seat to a vehicle floor, the seat rail assembly including: a first rail configured to be mounted to the vehicle floor, the first rail defining a sliding space; a second rail configured to support at least one vehicle seat mounted thereon, at least a portion of the second rail disposed within the sliding space of the first rail, the second rail being slidable relative to the first rail in a first direction or a second direction opposite the first direction, and having a first end corresponding to the first direction and a second end corresponding to the second direction; and first and second engagement assemblies disposed between the first and second rails, the first engagement assembly being configured to engage the second rail; a first engagement assembly disposed adjacent to a first end of the second rail, and a second engagement assembly disposed adjacent to a second end of the second rail, the first engagement assembly and the second engagement assembly each including a first engagement member and a second engagement member configured to move independently of each other in response to movement of the second rail relative to the first rail, the first engagement member being slidably provided on the second rail, and the second engagement member being slidably provided on the first rail between a first position and a second position, wherein when the second rail slides relative to the first rail, the second engagement member maintains contact with the first rail and the first engagement member maintains contact with the second rail. In some embodiments, the first engagement member of the first engagement assembly is biased in a first direction, the second engagement member of the first engagement assembly is biased in a second direction toward the first position, the first engagement member of the second engagement assembly is biased in the second direction, and the second engagement member of the second engagement assembly is biased in the first direction toward the first position. In some embodiments, the first engagement member of the first engagement assembly is biased in the first direction, the second engagement member of the first engagement assembly is biased in the second direction toward the first position, the first engagement member of the second engagement assembly is biased in the first direction, and the second engagement member of the second engagement assembly is biased in the second direction toward the first position.

[0010] The present disclosure also provides a mounting assembly for mounting a vehicle seat to a vehicle floor. In such an embodiment, the mounting assembly includes a first seat rail assembly and a second seat rail assembly, each of which is a seat rail assembly as described above.

[0011] The present disclosure also provides a method for assembling a vehicle seat rail assembly, the method including the steps of: providing a first rail having a sliding surface, the first rail having a first end and a second end opposite the first end; arranging a first engagement member on the sliding surface of the first rail, the first engagement member having a first surface that abuts against the sliding surface of the first rail and is slidable on the sliding surface; and urging the first engagement member toward the first end of the first rail. the second engaging member has a first surface that abuts against the second surface of the first engaging member and is slidable on the second surface; and the second engaging member is coupled to the first engaging member or the first rail with a second spring such that the second engaging member is biased toward the second end of the first rail. In some embodiments, the disclosed method further includes attaching the first rail to a second rail, the second rail having a sliding surface, and the second engaging member having a second surface that abuts against the sliding surface of the second rail and is slidable on the sliding surface. In further embodiments, the second engagement member maintains contact with the second rail and the first engagement member maintains contact with the first rail when the first rail slides relative to the second rail in a first direction or a second direction opposite the first direction. In further embodiments, the method of the present disclosure further includes attaching the second rail to a vehicle floor. In further embodiments, the method of the present disclosure further includes attaching at least one vehicle seat to the first rail.

[0012] The present disclosure also provides a method for assembling a vehicle seat rail assembly, the method including the steps of: providing a lower rail defining a sliding space; disposing at least a portion of an upper rail within the sliding space of the lower rail so that the upper rail is slidable in a first direction or a second direction opposite the first direction; and installing an engagement assembly between the lower rail and the upper rail, the engagement assembly including a lower engagement member and an upper engagement member configured to move independently of each other in response to movement of the upper rail relative to the lower rail, the lower engagement member being slidably mounted on the upper rail and the upper engagement member being slidably mounted on the lower engagement member between a first position and a second position, the lower engagement member being biased in the first direction and the upper engagement member being biased in the second direction toward the first position, wherein the upper engagement member maintains contact with the lower rail and the lower engagement member maintains contact with the upper rail when the upper rail slides in the first direction or the second direction relative to the lower rail. In some embodiments, an upper surface of the upper engagement member maintains contact with the inner surface of the lower rail, and a lower surface of the lower engagement member maintains contact with the surface of the upper rail. In further embodiments, the surface of the upper rail is an inclined surface, and the lower engagement member is slidably mounted on the inclined surface. In some embodiments, the method of the present disclosure further includes attaching the lower rail to a vehicle floor. In some embodiments, the method of the present disclosure further includes attaching at least one vehicle seat to the upper rail.

[0013] The present disclosure also provides a seat rail assembly including a first rail having longitudinally spaced slots and a second rail having a gearbox. In these embodiments, the gearbox includes at least one drive screw rotatable in a first rotational direction or a second rotational direction, the drive screw having a shaft and threads configured to engage with the longitudinally spaced slots of the first rail, lobes on the drive screw shaft configured to engage with the longitudinally spaced slots of the first rail and freely rotatable relative to the drive screw threads, and a lobe spring configured to bias the lobe in the first rotational direction. In some embodiments, the first rail defines a sliding space between the longitudinally spaced slots. In further embodiments, the second rail is at least partially disposed within the sliding space of the first rail. In some embodiments, the lobes have a limited range of rotation about the shaft. In some embodiments, the lobe has threads that are continuous with the threads of the drive screw. In some embodiments, the lobe has threads, and the threads of the lobe and the threads of the drive screw have equal pitches. In some embodiments, the lobe has a bore that receives a drive screw shaft, the drive screw shaft including a flat feature, the lobe bore having a pair of angled flat surfaces formed therein, and the lobe is rotatable relative to the shaft between a first position in which a first flat surface of the pair of angled flat surfaces abuts the flat feature and a second position in which a second flat surface of the pair of angled flat surfaces abuts the flat feature.

[0014] In some embodiments, the second rail includes a second gearbox, which includes at least one drive screw rotatable in a first rotational direction or a second rotational direction, the drive screw having a shaft and threads configured to engage with longitudinally spaced slots of the first rail, lobes on the drive screw shaft configured to engage with longitudinally spaced slots of the first rail, the lobes being freely rotatable relative to the drive screw threads, and a lobe spring configured to bias the lobe in the first rotational direction.

[0015] The present disclosure also provides a gearbox for a rail assembly. The gearbox of the present disclosure includes at least one drive screw rotatable in a first rotational direction or a second rotational direction, the drive screw having a shaft and threads configured to engage with longitudinally spaced slots of the rail, lobes on the drive screw shaft configured to engage with the longitudinally spaced slots of the rail and freely rotatable relative to the drive screw threads, and a lobe spring configured to bias the lobe in the first rotational direction. In some embodiments, the rail defines a sliding space between the longitudinally spaced slots. In some embodiments, the gearbox is at least partially disposed within the sliding space of the rail. In some embodiments, the lobe has a limited range of rotation about the shaft. In some embodiments, the lobe has a threaded portion that is continuous with the threaded portion of the drive screw. In some embodiments, the lobe has a threaded portion, and the threaded portion of the lobe and the threaded portion of the drive screw have an equal pitch. In some embodiments, the lobe has a bore that receives a drive screw shaft, the drive screw shaft including a flat feature, the lobe bore having a pair of angled flat surfaces formed therein, and the lobe is rotatable relative to the shaft between a first position in which a first of the pair of angled flat surfaces abuts the flat feature and a second position in which a second of the pair of angled flat surfaces abuts the flat feature.

[0016] The present disclosure also provides a seat rail assembly for mounting a vehicle seat to a vehicle floor, the seat rail assembly including: a first rail configured to be mounted to the vehicle floor, the first rail having longitudinally spaced slots and defining a sliding space; a second rail configured to support at least one vehicle seat mounted thereon, at least a portion of the second rail disposed within the sliding space of the first rail and slidable relative to the first rail in a first direction or a second direction opposite the first direction; and a gearbox disposed on the second rail. In these embodiments, the gearbox includes at least one drive screw rotatable in a first rotational direction or a second rotational direction, the drive screw having a shaft and threads configured to engage with longitudinally spaced slots in the first rail; lobes on the drive screw shaft configured to engage with longitudinally spaced slots in the first rail, the lobes being freely rotatable relative to the drive screw threads; and a lobe spring configured to bias the lobe in the first rotational direction. Also, in these embodiments, the seat rail assembly of the present disclosure further includes an engagement assembly provided within the sliding space of the first rail, the engagement assembly including a first engagement member and a second engagement member configured to move independently of each other in response to movement of the second rail relative to the first rail, the first engagement member being slidably provided on the second rail and the second engagement member being slidably provided on the first engagement member between a first position and a second position, the first engagement member being biased in a first direction and the second engagement member being biased in a second direction toward the first position, and when the second rail slides relative to the first rail in response to operation of the gearbox, the second engagement member maintains contact with the first rail and the first engagement member maintains contact with the second rail.

[0017] The present disclosure also provides a seat rail assembly for mounting a vehicle seat to a vehicle floor, the seat rail assembly including: a first rail configured to be mounted to the vehicle floor and defining a sliding space; a second rail configured to support a vehicle seat mounted thereon, at least a portion of which is disposed within the sliding space of the first rail and is slidable relative to the first rail in a first direction or a second direction opposite to the first direction; an engagement assembly disposed between the first rail and the second rail and slidably disposed on the inclined surface of the second rail; and a linear biasing member connecting the engagement assembly to the second rail such that the engagement assembly is biased toward a first position along the inclined surface of the second rail, wherein the engagement assembly maintains contact with both the inner surface of the first rail and the inclined surface of the second rail as the second rail slides relative to the first rail. [Brief explanation of the drawings]

[0018] The following drawings are intended to illustrate certain aspects of the present disclosure and should not be considered exclusive embodiments. The subject matter of the present disclosure is capable of considerable modification, alteration, combination, and equivalents in form and function without departing from the scope of the present disclosure.

[0019] [Figure 1] FIG. 1 is an isometric view of an exemplary seat rail assembly according to one or more embodiments of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional end view of the seat rail assembly of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional side view of the seat rail assembly of FIG. 1. [Figure 4] FIG. 2 is a cross-sectional top view of the seat rail assembly of FIG. 1. [Figure 5A] FIG. [Figure 5B] FIG. [Figure 6A] FIG. 4 is a side view of the engagement assembly of FIG. 3. [Figure 6B] FIG. 4 is a side view of the engagement assembly of FIG. 3. [Figure 7A] 10A-10C are partial side views of an engagement assembly illustrating an exemplary operation. [Figure 7B] 10A-10C are partial side views of an engagement assembly illustrating an exemplary operation. [Figure 8A] 10A-10C illustrate examples of interaction between the engagement assembly and the upper rail. [Figure 8B] 10A-10C illustrate examples of interaction between the engagement assembly and the upper rail. [Figure 9A] 10A and 10B are diagrams illustrating an example of relative movement between a lower engagement member and an upper engagement member. [Figure 9B] 10A and 10B are diagrams illustrating an example of relative movement between a lower engagement member and an upper engagement member. [Figure 10A] 11A-11C illustrate another example interaction between the engagement assembly and the upper rail. [Figure 10B] 11A-11C illustrate another example interaction between the engagement assembly and the upper rail. [Figure 11A] 10A-10C illustrate an exemplary lateral displacement control mechanism for noise reduction that is integrated with the lower rail in some embodiments. [Figure 11B] 10A-10C illustrate an exemplary lateral displacement control mechanism for noise reduction that is integrated with the lower rail in some embodiments. [Figure 12] 10A and 10B are diagrams illustrating an example of the installation of a lateral displacement control mechanism at the end of the upper rail. [Figure 13] FIG. 10 is a side view of another engagement assembly. [Figure 14A] 13A-13C show another engagement assembly. [Figure 14B] 13A-13C show another engagement assembly. [Figure 15A] 15A and 15B show a modification of the engagement assembly of FIG. 14. [Figure 15B] 15A and 15B show a modification of the engagement assembly of FIG. 14. [Figure 15C] 15A and 15B show a modification of the engagement assembly of FIG. 14. [Figure 15D]15A and 15B show a modification of the engagement assembly of FIG. 14. [Figure 16A] 13A-13C show another engagement assembly. [Figure 16B] 13A-13C show another engagement assembly. [Figure 16C] 13A-13C show another engagement assembly. [Figure 17] 10 illustrates another cam engagement assembly according to one or more alternative embodiments. [Figure 18] 15C illustrates an example of the operation of the engagement assembly of FIG. 15B. [Figure 19] 13A-13C show another engagement assembly. [Figure 20] FIG. 1 illustrates a gearbox that can be used to drive the seat rail assembly described herein. [Figure 21] FIG. 21 is a partial exploded view of the gearbox of FIG. [Figure 22] 10A and 10B are diagrams illustrating an example of the operation of a drive system of a gearbox. [Figure 23] FIG. 23 is an end view of the drivetrain of FIG. 22. [Figure 24A] 10A-10C illustrate an example of the operation of a non-spring biased lobe (non-active lobe) in a seat rail assembly. [Figure 24B] 10A-10C illustrate an example of the operation of a spring-biased lobe (active lobe) in a seat rail assembly. [Figure 25] FIG. 10 illustrates an example of a drive screw configured to limit rotation of the lobes. [Figure 26A] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 26B] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 27A] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 27B] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 28A] FIG. 1 illustrates an example of a lobe, according to one or more embodiments of the present disclosure. [Figure 28B] FIG. 1 illustrates an example of a lobe, according to one or more embodiments of the present disclosure. [Figure 29] FIG. 10 illustrates another gearbox that can be used to drive the seat rail assemblies described herein. [Figure 30] FIG. 30 is a side cross-sectional view of the gearbox of FIG. 29. [Figure 31] FIG. 31 is a partial exploded view of the gearbox of FIG. [Figure 32] 32 is a diagram showing an example of the operation of the drive system of the gearbox in FIG. 31. FIG. [Figure 33] 30 is a partial cross-sectional view showing an example of the operation of the gearbox of FIG. 29. [Figure 34A] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 34B] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 35A] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. [Figure 35B] FIG. 10 illustrates an example of gearbox driveline operation to remove system slop. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present disclosure relates to a seat rail assembly, and more particularly to a seat rail assembly that supports the position of a vehicle seat and allows for easy operation of the seat without rattle or unwanted resistance.

[0021] FIG. 1 is an isometric view of an exemplary seat rail assembly 100 according to one or more embodiments of the present disclosure. FIG. 2 is a cross-sectional end view of the seat rail assembly 100 of FIG. 1. FIG. 3 is a cross-sectional side view of the seat rail assembly 100 of FIG. 1. FIG. 4 is a cross-sectional top view of the seat rail assembly 100 of FIG. 1. The seat rail assembly 100 is merely one example of a seat rail assembly embodying the principles of the present disclosure. Various alternative designs and configurations of the seat rail assembly 100 may be used without departing from the scope of the present disclosure. The seat rail assembly 100 supports at least one vehicle seat (not shown) on a vehicle floor (not shown) in a manner that allows movement of the vehicle seat relative to the vehicle floor. It should also be understood that two (or more) seat rail assemblies 100 may be used to support the left and right sides (and possibly intermediate regions) of the vehicle seat. For simplicity, one seat rail assembly 100 is shown and described, but it should be understood that any number of seat rail assemblies 100 may be used without departing from the present disclosure. Also, while the present seat rail assembly 100 is described herein with respect to mounting a vehicle seat (or multiple vehicle seats) to a vehicle floor, the seat rail assembly 100 may also be used to mount the vehicle seat to another surface of the vehicle, such as a ceiling or sidewall. Additionally, while the present subject matter is disclosed as a rail assembly for movably mounting a vehicle seat to a vehicle surface, the seat rail assembly 100 may also be used to movably mount other objects, such as ottomans, tables, benches, entertainment equipment, etc., relative to a vehicle surface. Furthermore, while the seat rail assembly 100 is described as being used in automotive and vehicular applications, the present subject matter may also be used in a variety of other non-automotive applications where it is desirable to reduce rattle between moving components. All such applications are considered within the scope of the present disclosure.

[0022] The seat rail assembly 100 includes a lower rail 102 and an upper rail 104. The lower rail 102 defines an internal cavity or sliding space 106 in which the upper rail 104 is slidably mounted. The upper rail 104 can slide relative to the lower rail 102 with or without an external drive source as described herein. Thus, the upper rail 104 can slide relative to the lower rail 102 with or without powered operation. In this manner, the upper rail 104 is slidably mounted on the lower rail 102 so as to move (or slide) forward and backward as indicated by arrow X (i.e., the upper rail 104 can slide forward or backward, oppositely). For example, when installed in a vehicle, the lower rail 102 extends in an X-direction, which is the fore-and-aft direction of the vehicle seat, and has a width in a Y-direction. As described herein, the lower rail 102 is mounted (i.e., positioned or fixed in position) on the vehicle floor. Similarly, the vehicle seat is mounted (ie, placed or secured in place) on the upper rails 104 as described herein.

[0023] Figure 5A is a cross-sectional end view of the lower rail 102. Figure 5B is a partial perspective view of the end of the upper rail 104. The lower rail 102 includes a bottom plate portion 108, a pair of outer plate portions 110 extending upward from the left and right ends of the bottom plate portion 108, upper plate portions 112 extending inward in the left-right direction Y from the upper ends of the left and right outer plate portions 110, and inner plate portions 114 extending downward from the inner ends of the left and right upper plate portions 112.

[0024] The lower rail 102 defines a sliding space 106. The sliding space 106 is a space in which at least a portion of the upper rail 104 is slidably accommodated. The sliding space 106 is surrounded by a bottom plate portion 108, left and right outer plate portions 110, left and right top plate portions 112, and left and right inner plate portions 114 of the lower rail 102. The sliding space 106 accommodates a lower portion of the upper rail 104. The sliding space 106 opens upward from the space between the left and right inner plate portions 114. The upper rail 104 is attached so that the upper portion 116 of the upper rail 104 protrudes from the open area between the left and right inner plate portions 114 of the lower rail 102. In addition, the sliding space 106 is partitioned and includes a central space 106a defined between the left and right inner plate portions 114, and a pair of left and right side spaces 106b, 106c defined between the outer plate portion 110 and the inner plate portion 114 and arranged on either side of the central space 106a.

[0025] 1, a plurality of slots 118 (lock holes) are formed in one or both of the left and right inner plate portions 114. The slots 118 are formed intermittently in the X direction and are used to fix the position of the upper rail 104 relative to the lower rail 102.

[0026] The upper rail 104 includes a pair of side panels 120. As shown in FIGS. 1 and 5B , the pair of side panels 120 have overlapping portions 122a, 122b extending in the X direction. Each side panel 120 is curved or arc-shaped to enclose at least a portion of the left and right inner panel portions 114 of the lower rail 102. In the illustrated example, each side panel 120 is generally U-shaped in cross section and includes a downwardly extending side wall portion 124, an upwardly extending side wall portion 126, and a bottom wall portion 128 connecting the side wall portions 124 and 126 to each other. The downwardly extending side wall portion 124 and the upwardly extending side wall portion 126 are spaced apart from each other in the Y direction, and the inner panel portion 114 of the lower rail 102 extends downward between the side wall portions 124 and 126. When assembled, the side wall portions 124 of the side plate 120 are positioned between the inner plate portions 114 of the lower rail 102 and in the central space 106a of the sliding space 106, and the side wall portions 126 of the side plate 120 are positioned in the left and right side spaces 106b, 106c. In the illustrated example, a pair of spacers 502a, 502b are used to laterally support the side plate 120 at a desired width.

[0027] Rollers 130 are provided on and supported by the upper rail 104. In the illustrated example, the rollers 130 are rotatably mounted on the upwardly extending sidewall portion 126. The rollers 130 roll on an upper surface 132 of the bottom plate portion 108 of the lower rail 102, thereby slidably supporting the upper rail 104 relative to the lower rail 102. As will be described below, in some embodiments, the rollers 130 are coupled to the upper rail 104 via sliding members disposed on an inner surface 129 of the bottom wall portion 128 of the upper rail 104.

[0028] Referring to FIG. 3, the upper rail 104 has at least one inclined surface 304. As shown, a pair of inclined surfaces 304a, 304b is provided at both ends 302a, 302b of the upper rail 104. The inclined surfaces 304 are formed on the sidewall portions 126 of the upper rail 104. As will be described later, an engagement assembly 306 slidably abuts each inclined surface 304. Specifically, a pair of engagement assemblies 306a, 306b slidably abuts each of the inclined surfaces 304a, 304b. Each engagement assembly 306a, 306b also abuts the lower surface 134 (see FIG. 2) of the top plate portion 112 of the lower rail 102. In this manner, the upper rail 104 is constrained within the sliding space 106 of the lower rail 102 between the bottom plate portion 108 and the top plate portion 112 of the lower rail 102 via the rollers 130 and the engagement assemblies 306a, 306b.

[0029] FIG. 5B shows an example of an upper rail 104 that can be used in the seat rail assembly of FIGS. 1 to 4. As shown, inclined surfaces 304a and 304b extend in the X direction along the upper rail 104. The inclined surfaces 304a and 304b slope upward in the Z direction as they approach each other (and slope downward in the Z direction as they move away from each other, i.e., toward each end 302a, 302b). For example, as shown in FIG. 3, the inclined surface 304a adjacent to the first end 302a on the left side of the figure has a positive slope, while the inclined surface 304b adjacent to the second end 302b on the right side of the figure has a negative slope. In other words, the slopes of the inclined surfaces 304a and 304b have opposite signs (e.g., the inclined surface 304a has a positive (+) slope and the inclined surface 304b has a negative (-) slope, or vice versa). The inclined surfaces 304a, 304b are inclined toward the lower surface 134 of the top plate portion 112 of the lower rail 102. Furthermore, regardless of whether the signs of the slopes of the inclined surfaces 304a, 304b are the same, the magnitudes of the slopes of the inclined surfaces 304a, 304b may be the same (i.e., the absolute values ​​may be equal but the signs may be opposite). Alternatively, the magnitudes of the slopes of the inclined surfaces 304a, 304b may be different from each other. Additionally, the lengths of the inclined surfaces 304a, 304b may be the same or different from each other. Also, for example, the inclined surfaces 304a, 304b may be inclined in the same direction (i.e., both have a positive (+) or negative (-) slope) and may extend in the same direction toward either the first end 302a or the second end 302b of the upper rail 104.

[0030] 6A and 6B show an exemplary engagement assembly 306 featuring a dual wedge design in accordance with one or more embodiments of the present disclosure. Specifically, FIG. 6A shows the left engagement assembly 306a of FIG. 3, and FIG. 6B shows the right engagement assembly 306b of FIG. 3. The pair of engagement assemblies 306a, 306b are located at opposite ends 302a, 302b of the upper rail 104 and may be identical to each other. The engagement assemblies 306a, 306b are disposed on the upper rail 104 within left and right lateral spaces 106b, 106c of the sliding space 106 defined by the lower rail 102. The engagement assemblies 306a, 306b are slidable on the inclined surfaces 304a, 304b of the upper rail 104.

[0031] Each engagement assembly 306a, 306b includes a lower engagement member 602 and an upper engagement member 604. The lower engagement member 602 and the upper engagement member 604 are each configured as wedge-shaped members such that the engagement assembly 306 embodies a dual wedge design. The lower engagement member 602 has a lower inclined surface 606 that is slidable against the inclined surfaces 304a, 304b of the upper rail 104, thereby allowing the lower engagement member 602 to slide relative to the upper rail 104. The lower engagement member 602 also has an upper inclined surface 608. The upper engagement member 604 has a lower contact surface (not visible in the figure) that is slidable against the upper inclined surface 608 of the lower engagement member 602, thereby allowing the upper engagement member 604 to slide on the upper inclined surface 608 of the lower engagement member 602. The upper engagement member 604 also has an upper surface 610 that is slidable against the lower surface 134 of the top plate portion 112 of the lower rail 102. In the illustrated example, a sloped channel or track 612 is defined in the lower engagement member 602. The upper engagement member 604 has a pair of retention legs 614 a, 614 b that slide within the track 612, thereby slidably retaining the lower contact surface of the upper engagement member 604 in contact with the upper sloped surface 608 of the lower engagement member 602. The lower engagement member 602 also has a stop 616 formed to contact the retention leg 614 a of the lower engagement member, thereby preventing further movement of the upper engagement member 604 within the track 612.

[0032] Each engagement assembly 306a, 306b also includes a tension spring 620 and a torsion spring 622. The tension spring 620 has a first end 624 that is coupled to the upper rail 104 and a second end 626 that is coupled to the lower engagement member 602. The tension spring 620 biases the lower engagement member 602, as described below. In other examples, the tension spring 620 is replaced with another type of biasing element, such as a torsion spring or compression spring. The tension spring 620 applies a biasing force to the lower engagement member 602 that is independent of the direction of movement of either the lower rail 102 or the upper rail 104. In other examples (not shown), the tension spring 620 is positioned on the opposite side so that the biasing force it applies is 180 degrees reversed from that shown.

[0033] The torsion spring 622 biases the upper engagement member 604 toward the stopper 616. In other examples, the stopper 616 may be provided at the opposite end of the track 612, in addition to or instead of the stopper 616 shown. Specifically, the torsion spring 622 is mounted on an embossment 621 formed on the lower engagement member 602 and applies a force to a back surface 623 of the upper engagement member 604. As a result, as shown in FIGS. 6A and 6B , the torsion spring 622 biases the upper engagement member 604 toward an initial position in which the upper engagement member 604 abuts against the stopper 616 of the lower engagement member 602. As will be described below, when acted upon by the lower rail 102, the upper engagement member 604 can move along the channel or track 612 relative to the lower engagement member 602 in a direction opposite to the stopper 616 against the biasing force applied by the torsion spring 622. As shown in FIG. 7A , the upper engagement member 604 can continue to move in a direction 702 opposite the stop 616 until it reaches an extreme position 704 where further movement is prevented by the torsion spring 622. In this manner, the torsion spring 622 also functions to prevent the upper engagement member 604 on the lower engagement member 602 from moving beyond the extreme position 704, as described below. Similarly, the torsion spring 622 applies a biasing force to the upper engagement member 604 that is independent of the direction of movement of either the lower rail 102 or the upper rail 104. In the illustrated example, the lower engagement member 602 and the upper engagement member 604 are biased in opposite directions. Also, in the illustrated example, the lower engagement member 602 and the upper engagement member 604 are biased toward the maximum thickness of the engagement assembly 306. In other examples not shown, both the lower engagement member 602 and the upper engagement member 604 are biased by a tension spring, a compression spring, a torsion spring, or another type of spring, etc.

[0034] The relative sliding movement between the lower engagement member 602 and the upper engagement member 604 changes the distance between the lower surface 606 of the lower engagement member 602 and the upper surface 610 of the upper engagement member 604 (i.e., the stack height), which allows each of the engagement assemblies 306 a, 306 b to maintain continuous support and contact between the inclined surfaces 304 a, 304 b of the upper rail 104 and the lower surface 134 of the top plate portion 112 of the lower rail 102, despite unevenness and height variations due to vehicle movement or manufacturing, as described above. For example, in FIG. 7A , the stack height between the upper engagement member 604 and the lower engagement member 602 (i.e., the distance between the lower surface 606 of the lower engagement member 602 and the upper surface 610 of the upper engagement member 604) is smallest when the upper engagement member 604 is in the extreme position 704 and is greatest when the upper engagement member 604 is in the initial position shown in FIGS. 6A and 6B .

[0035] In this manner, the engagement assembly 306 maintains contact between the lower rail 102 and the upper rail 104. Specifically, the lower engagement member 602 maintains contact with the upper rail 104, and the upper engagement member 604 maintains contact with the lower rail 102. Note that in some examples, one or more of the engagement assemblies 306 may be inverted upside down so that the upper engagement member 604 maintains contact with the upper rail 104 and the lower engagement member 602 maintains contact with the lower rail 102. In the illustrated example, the engagement assembly 306 contacts the inner surface of the lower rail 102, but in other examples, the engagement assembly 306 may contact the outer surface of the lower rail 102. Similarly, in the illustrated example, the engagement assembly 306 contacts the inner surface of the upper rail 104, but in other examples, the engagement assembly 306 may contact the outer surface of the upper rail 104. As described above, the lower engagement member 602 maintains contact with the surface of the upper rail 104, and the upper engagement member 604 maintains contact with the surface of the lower rail 102. The surface of the lower rail 102 and / or the surface of the upper rail 104 that the engagement assembly 306 contacts may be an inclined surface. Furthermore, the portion of the engagement assembly 306 that slides on the inclined surface may be a side surface of the engagement assembly 306. For example, the side surface of the upper engagement member 604 may slide on the inclined surface of the upper rail 104, and the side surface of the lower engagement member 602 may slide on the inner surface of the lower rail 102. In this way, the engagement assembly 306 can be used to remove lateral rattles in the lower rail 102 and the upper rail 104 in addition to (or instead of) removing vertical rattles.

[0036] Figure 7A illustrates the movement or sliding path of the upper engagement member 604 on the lower engagement member 602, while Figure 7B illustrates the movement or sliding path of the lower engagement member 602 relative to the upper rail 104. Specifically, Figure 7B illustrates the lower engagement member 602 positioned on the inclined surface 304 of the upper rail 104 in an initial or nominal position 710, from which it is movable forward or backward to a first extreme position 712 or a second extreme position 714. The lower engagement member 602 supports the upper engagement member 604, and the two members are movable or slidable together relative to the upper rail 104 between the first extreme position and the second extreme position. The tension spring 620 biases the lower engagement member 602 toward the second extreme position 714, and when the upper rail 104 moves in the direction 716 relative to the lower rail 102, friction causes the lower engagement member 602 (while supporting the upper engagement member 604, which is prevented from moving relative to the lower engagement member 602 by the stopper 616) to move downward along the inclined surface 304 toward the sliding direction 718 with little effect on the sliding force / resistance.

[0037] The slope or gradient of the inclined surfaces 304 a, 304 b of the upper rail 104 helps accommodate any variations in the gap between the lower rail 102 and the upper rail 104 that may occur during manufacturing or vehicle movement. As shown in FIG. 7B , when the upper engagement member 604 is fully biased toward the stopper 616 of the lower engagement member 602 (in the sliding direction 718), the upper surface 610 of the upper engagement member 604 when the lower engagement member 602 is in the second extreme position 714 is higher than when the lower engagement member 602 is in the first extreme position 712 due to the slope of the inclined surfaces 304 a, 304 b of the upper rail 104.

[0038] Referring again to FIG. 7A , which illustrates the sliding or movement path of the upper engagement member 604 relative to the lower engagement member 602, the upper engagement member 604 is configured to slide within a track 612 formed in the lower engagement member 602 and is constrained between a first extreme position (where the upper engagement member 604 abuts a stop 616) and a second extreme position (where the upper engagement member 604 moves fully in the direction 702 until a torsion spring 622 limits further movement). In another example, the stop 616 may be located at the opposite end of the track 612. Placing the stop 616 at one end of the track 612 allows the upper engagement member 604 to slide over the lower engagement member 602 when assembled. In yet another example, the stop 616 may be located at both ends of the track 612, in which case the upper engagement member 604 may snap onto the track 612 of the lower engagement member 602 when assembled.

[0039] When not acted upon by sufficient frictional forces generated by movement of the lower rail 102 or upper rail 104 (i.e., when installed in a vehicle with a seat and / or a user sitting on the seat), the engagement assembly 306 is designed to be disposed in an initial or nominal position 710, as shown in FIG. 7B. When in the initial or nominal position 710, the lower engagement member 602 is substantially centered along the length of the inclined surface 304 of the upper rail 104, and the upper engagement member 604 is biased to its extreme position against stop 616 in the direction of the spring force applied by torsion spring 622 (see FIG. 7A). In the initial or nominal position 710, when the lower engagement member 602 is centered along the inclined surface 304, the engagement assembly 306 has a sufficient range of movement along the inclined surface 304 of the upper rail in either direction 716 or the opposite direction 720 to accommodate expected variations in vertical stack height between the lower rail 102 and the upper rail 104 that may be encountered (due to manufacturing tolerances) as the upper rail 104 moves relative to the lower rail 102. The upper engagement member 604 also has a sufficient range of movement along the inclined track 612 of the lower engagement member 602 to accommodate variations in vertical stack height between the upper rail 104 and the lower rail 102 that may be encountered as the upper rail 104 moves in direction 720 relative to the lower rail 102. This relative movement between the upper engagement member 604 and the lower engagement member 602 ensures constant contact between the lower rail 102 and the upper rail 104 while simultaneously preventing any binding between the lower rail 102 and the upper rail 104. For example, when the vehicle seat and upper rail 104 move in direction 716, the lower engagement member 602 moves downward in direction 718 along the sloped surface 304 of the upper rail 104 with little effect on the sliding force or resistance. On the other hand, when the vehicle seat and upper rail 104 move in a direction 720 opposite direction 716, the upper engagement member 604 moves downward in direction 702 along the track 612 of the lower engagement member 602 with little effect on the sliding force or resistance.This relative movement between the upper and lower engagement members 604, 602 ensures constant contact between the upper and lower rails 104, 102 while preventing binding.

[0040] For example, if the gap between the lower rail 102 and the upper rail 104 decreases while the upper rail 104 is moving in direction 702, the upper engagement member 604 moves in the downward direction 702. Alternatively, if the gap remains constant or increases while the upper rail 104 is moving in direction 720, no binding occurs and the upper engagement member 604 does not move. If the gap between the lower rail 102 and the upper rail 104 increases while the upper rail 104 is moving in direction 720, the tension spring 620 biases the lower engagement member 602 along the ramp surface 304 toward an initial or nominal position to maintain continuous contact between the upper rail 104 and the lower rail 102.

[0041] 8A and 8B illustrate another aspect of the interaction between the engagement assembly 306 and the upper rail 104. As shown in FIG. 8A, the upper rail 104 has slots 802a and 802b that receive portions of the lower engagement member 602. The slots 802a and 802b are disposed below the inclined surfaces 304a and 304b, respectively. The slots 802a and 802b are inclined in a direction that matches the corresponding inclined surfaces 304a and 304b. Thus, one slot 802a has the same inclination as the inclined surface 304a, and the other slot 802b has the same inclination as the other inclined surface 304b. For example, the slots 802 and their corresponding inclined surfaces 304 can be parallel to one another (i.e., the slot 802a is parallel to the inclined surface 304a, and the slot 802b is parallel to the inclined surface 304b). In this manner, the lower engagement member 602 (and engagement assembly 306) moves linearly along a linear path defined by the slots 802 and their corresponding ramp surfaces 304. Therefore, in instances where the orientation of one or both of the ramp surfaces 304a, 304b is changed (i.e., flipped), the orientation of the slots 802a, 802b is changed accordingly. The lower engagement member 602 of the engagement assemblies 306a, 306b also has a pair of spaced legs 810, 812 that define a channel 814. When assembled, the lower engagement member 602 rests on the ramp surface 304, with the spaced legs 810, 812 straddling the sidewall portion 126 of the upper rail 104 and the portion 816 of the sidewall portion 126 adjacent the ramp surface 304 inserted into the channel 814 of the lower engagement member 602. Accordingly, the spaced apart legs 810, 812 and the corresponding channel 814 formed thereby are sized according to the thickness of the portion 816 of the sidewall portion 126 of the upper rail 104. The lower engagement member 602 also includes a guide pin 818. The guide pin 818 is positioned to be received in the corresponding guide slot 802a, 802b. The guide pin 818 is located on one of the legs 812 and protrudes therefrom into the channel 814. However, the guide pin 818 may also be located on the other leg 810 or on both legs 810, 812.When assembled, the lower engagement member 602 rests on the inclined surface 304, the portion 816 of the sidewall portion 126 adjacent the inclined surface 304 is inserted into the channel 814 of the lower engagement member 602, and the guide pin 818 is supported in the guide slot 802 to help retain the engagement assembly 306 on the upper rail 104.

[0042] 9A and 9B illustrate the relative movement of a lower engagement member 602 and an upper engagement member 604 in accordance with one or more embodiments of the present disclosure. As shown in FIG. 9A , the lower engagement member 602 moves along the inclined surface 304 of the upper rail 104 along a first path 902, and the upper engagement member 604 moves along the upper inclined surface 608 of the lower engagement member 602 (and within its channel or track 612) along a second path 904. The inclined surface 304 is oriented at various angles θ′ relative to the horizontal, and the corresponding first path 902 is also oriented at various angles θ′ relative to the horizontal. In the illustrated example, the inclined surface 304 and the corresponding first path 902 are oriented at an angle θ of 6 degrees. Additionally, the upper inclined surface 608 of the lower engagement member 602 (and the channel or track 612) is oriented at various angles θ relative to the horizontal, and the corresponding second path 904 is also oriented at various angles θ relative to the horizontal. In the illustrated example, the upper angled surface 308 and corresponding second path 904 are oriented at an angle θ of 6 degrees. The angles θ and θ′ may vary from one another depending on the amount of play between the upper rail 104 and the lower rail 102 and based on the amount of travel of the upper rail 104 and the lower rail 102.

[0043] FIG. 9B illustrates the extent of movement of the lower engagement member 602 and the upper engagement member 604 of FIG. 9A in accordance with one or more embodiments of the present disclosure. Tension spring 620 applies a force to lower engagement member 602, thereby pulling lower engagement member 602 (and engagement assembly 306) as indicated by arrow 906. The system is designed to provide varying amounts of movement X′ for lower engagement member 602 in direction 906. For example, lower engagement member 602 is configured to allow up to 8 mm of movement X′ in direction 906 from an initial or nominal position. In the illustrated example, the movement of lower engagement member 602 is constrained or limited between walls 910, 912 of upper rail 104. For example, slot 802 (see FIG. 8A) is designed with appropriate dimensions to allow the desired amount of movement X′ in direction 906 from an initial or nominal position. Additionally, torsion spring 622 applies a force to upper engagement member 604, thereby biasing upper engagement member 604 in the direction indicated by arrow 908, and in use, upper engagement member 604 can move a distance X" in the direction opposite arrow 908. For example, upper engagement member 604 is configured to allow a maximum movement X" of 8 mm in the direction opposite arrow 908.

[0044] 10A and 10B show another example of the interaction between the upper rail 104 and the engagement assembly 306. In this example, the lower engagement member 602 includes a single wall 810 and does not have a guide pin.

[0045] 11A and 11B show an example of a lateral displacement control mechanism 1102 for reducing rattle between various components, thereby reducing noise. The lateral displacement control mechanism 1102 is provided on the inner surface of the U-shaped side plate 120 of the upper rail 104. As shown, the lateral displacement control mechanism 1102 is attached to the inner surface 1104 of the sliding space 106 defined between the side wall portion 124, the side wall portion 126, and the bottom wall portion 128 of the side plate 120.

[0046] 11B illustrates a lateral displacement control mechanism 1102 according to one or more embodiments. In the illustrated example, each lateral displacement control mechanism 1102 is a U-shaped member including an inner wall portion 1124, an outer wall portion 1126, and a curved bottom wall portion 1128 connecting the inner wall portion 1124 and the outer wall portion 1126. When assembled, the inner wall portion 1124, the outer wall portion 1126, and the bottom wall portion 1128 define a channel 1130 through which the left and right inner plate portions 114 of the lower rail 102 extend. When assembled, the inner wall portion 1124 abuts the downwardly extending side wall portion 124 of the upper rail 104, the outer wall portion 1126 abuts the upwardly extending side wall portion 126 of the upper rail 104, and the curved bottom wall portion 1128 abuts the bottom wall portion 128 of the upper rail 104. The lateral displacement control mechanism 1102 includes a pair of outer and inner locking tabs 1132, 1134 that engage the edges of the notches 1202 formed in the upper rail 104, as described below. One or more crush ribs 1136 are provided within the channel 1130 to ensure sustained contact and reduce rattle. The crush ribs 1136 are provided on the inner surface of the inner wall portion 1124 and contact the left and right inner plate portions 114 (see FIG. 2 ) of the lower rail 102 when fully assembled. The crush ribs 1136 can have various configurations and / or dimensions. For example, the crush ribs 1136 have a rounded, elongated shape as shown. In other examples, leaf springs are used instead of crush ribs. In other examples, both crush ribs and leaf springs (located on the same or opposite sides of each other) are used. The lateral displacement control mechanism 1102, including the crush ribs 1136, can be made of a non-metallic material, such as plastic, to avoid metal-to-metal contact. A lateral displacement control mechanism 1102 attached to the upper rail 104 contacts the left and right inner plate portions 114 of the lower rail 102, thereby ensuring continuous contact between the lower rail 102 and the upper rail 104 while avoiding metal-to-metal contact. Additionally, holes 1140 are formed in the lateral displacement control mechanism 1102 to provide space to accommodate the rollers 130 and to provide a drain for debris to exit the system.

[0047] 12 shows an example of the placement of the lateral displacement control mechanism 1102 at the end of the upper rail 104. In the example shown, a notch 1202 is formed in the end of the upper rail 104 to accommodate the lateral displacement control mechanism 1102. As described above, the outer and inner locking tabs 1132, 1134 of the lateral displacement control mechanism 1102 snap the lateral displacement control mechanism 1102 into place, and the outer and inner locking tabs 1132, 1134 engage the edges of the notch 1202, securing the lateral displacement control mechanism 1102 within the channel 1130. The notch 1202 also provides space to accommodate the roller 130 and a drain for debris to exit the system through a hole 1140 in the lateral displacement control mechanism 1102.

[0048] FIG. 13 illustrates another engagement assembly 1300 according to one or more alternative embodiments. In the illustrated example, the engagement assembly 1300 includes a single engagement member 1302 (or a single “wedge”). Accordingly, the engagement assembly 1300 is referred to as a single-wedge design, in contrast to the engagement assembly 306 described above, which utilizes a pair of engagement members 602, 604 (i.e., a pair of “wedges”) and is referred to as a dual-wedge design. The engagement member 1302 has a lower surface 1304 that, when assembled, slides against the inclined surface 304 of the upper rail 104. Additionally, the engagement member 1302 has an upper surface 1306 that, when assembled, slides against the lower surface 134 (not shown in FIG. 13 ) of the top plate portion 112 of the lower rail 102.

[0049] 14A and 14B illustrate another engagement assembly 1400 according to one or more alternative embodiments. This engagement assembly 1400 uses a spring-biased rotation mechanism (or cam), as described below, in contrast to the engagement assembly 306 described above, which uses a pair of spring-biased engagement members 602, 604 (i.e., a pair of spring-biased "wedges"). FIG. 14A is an exploded view of the engagement assembly 1400. FIG. 14B is a front cross-sectional view of the alternative engagement assembly 1400 when assembled on the upper rail 104, absent the sliding feature described below.

[0050] As shown, the engagement assembly 1400 includes a hub member 1402, a cam member 1404, and a slide member 1406. The hub member 1402 is attached to the upper rail 104. In the illustrated example, the hub member 1402 is attached to a tab 1410 on the upper rail 104. The hub member 1402 has an internal bore 1408 that is keyed to fit over the tab 1410 to prevent rotation of the hub member 1402 relative to the tab 1410. The hub member 1402 has an outer circular slide surface 1412 configured on which the cam member 1404 can rotate. The cam member 1404 has a bore 1414 and is attached to the hub member 1402 such that the bore 1414 of the cam member 1404 slides over the outer circular slide surface 1412 of the hub member 1402. The cam member 1404 also has a cam surface 1416 on which the slide member 1406 is positioned. The slide member 1406 has a lower surface that engages with the cam surface 1416. The slide member 1406 also has an upper surface 1418 that engages with the lower surface 134 (not shown in FIG. 13 ) of the top plate portion 112 of the lower rail 102. Although not shown, a biasing member (e.g., a torsion spring) is supported on the hub member 1402 and has a free end that is retained by a feature (e.g., an embossment) on the cam member 1404, thereby biasing the cam member 1404 toward an initial position and returning it to that initial position when the cam member 1404 is rotated clockwise or counterclockwise from the initial position. Alternatively, a coil spring may be used to bias the cam member 1404. In this case, as described in other embodiments above, a first end of the coil spring is coupled to the upper rail 104 and a second end of the coil spring is coupled to the cam member 1404. For example, a torsion or tension spring may be used to bias the cam member 1404, resulting in a spring-biased cam. In the illustrated example, the sliding member 1406 is not spring-biased, but in other examples, it may be spring-biased by a torsion or tension spring. In some examples, a feature 1420 is provided to help retain the hub member 1402 on the tab 1410 of the upper rail 104, such as a deformable feature for retaining the bore 1408 of the hub member 1402 on the upper radius of the tab 1410.The feature 1420 may be a snap-fit ​​feature (or finger) integral with the hub member 1402 that snaps into place when the hub member 1402 is inserted over the tab 1410, thereby securing the hub member 1402 to the tab 1410 of the upper rail 104.

[0051] The slide member 1406 can have a variety of underside shapes. FIGS. 15A-15D illustrate alternative underside configurations of the slide member 1406 according to various embodiments of the present disclosure. Specifically, FIG. 15A illustrates the slide member 1406 of FIG. 14 , which has a circular slide surface 1502 configured to fully contact the cam surface 1416 of the cam member 1404, as indicated by arrow 1504. As shown in FIG. 15A , this design improves contact / engagement between the cam member 1404 and the slide member 1406. As the upper rail 104 moves relative to the lower rail 102, the curvature of the slide surface 1502 matches the curvature of the cam surface 1416, allowing the slide member 1406 to maintain full contact with the cam member 1404 during rotation of the cam member 1404, as indicated by arrow 1506. In some examples, the slide member 1406 may include a retention leg mechanism that hooks around a portion of the cam member 1404 such that the slide member 1406 is slidably retained on the cam member 1404. Also, the cam lock angle may vary within a tolerance range from, for example, about 8 degrees.

[0052] FIG. 15B illustrates the slide member 1406 of FIG. 14 having an angled flat slide surface 1508 configured to contact the cam surface 1416 of the cam member 1404 at a single contact point 1510. The single contact point 1510 is perpendicular to the angled flat slide surface 1508. The angled flat slide surface 1508 can improve contact / engagement with the lower surface 134 (of the lower rail 102) because the single contact point 1510 provides a degree of freedom in both directions of movement. Additionally, the geometry of the cam member 1404 and its cam surface 1416 can be modified to maintain a constant locking angle. Operation of a slide member 1406 incorporating an angled flat slide surface 1508 is described below with reference to FIG. 18.

[0053] 14, the sliding member 1406 has a flat sliding surface 1512 (i.e., not angled) and is configured to contact the cam surface 1416 of the cam member 1404 at a single contact point 1514 that is perpendicular to the flat sliding surface 1512. The flat sliding surface 1512 can improve contact / engagement with the lower surface 134 (of the lower rail 102) because the single contact point 1514 provides a degree of freedom in both directions of movement. Additionally, the geometry of the cam member 1404 and its cam surface 1416 can be varied to maintain a constant locking angle.

[0054] FIG. 15D illustrates the sliding member 1406 of FIG. 14, with the sliding member 1406 having a semicircular or partial circular sliding surface 1516. Compared to the circular sliding surface 1502 of FIG. 15A, the semicircular or partial circular sliding surface 1516 of FIG. 15D has a shorter length and therefore fewer contact points 1518. It should be understood that the length of the semicircular or partial circular sliding surface 1516 of FIG. 15D may be longer or shorter than shown. The semicircular or partial circular sliding surface 1516 of FIG. 15D also improves contact / engagement with the lower surface 134 (of the lower rail 102).

[0055] 16A-16C show another engagement assembly 1600 that uses a cam 1404, according to one or more alternative embodiments. In this example, a single cam 1404 is used. As shown, the cam 1404 can rotate, as indicated by arrow 1602, to accommodate (or accommodate) variations in height 1604 of the lower rail 102 that may result from manufacturing a long lower rail 102, as described above.

[0056] 16B and 16C illustrate an example of the operation of engagement assembly 1600. In FIG. 16B, the lower rail 102 and upper rail 104 are moving relative to one another, with the lower rail 102 moving in direction 1612 and the upper rail moving in direction 1614, with a cam spring force 1616 acting on cam member 1404. The direction 1612 in which the lower rail 102 moves is opposite the direction in which spring force 1616 acts, resulting in a force 1620 being applied to cam surface 1416, as shown. This force 1620 includes both a normal force and an optional friction force. The friction force may be constant based on the spring output.

[0057] In Figure 16C, the lower rail 102 and upper rail 104 are moving in opposite directions, as shown in Figure 16B, with the lower rail 102 moving in direction 1632 and the upper rail moving in direction 1634, and cam member 1404 being subjected to cam spring force 1616 as in Figure 16B. The direction 1632 in which the lower rail 102 moves is the same direction as the direction in which spring force 1616 acts, resulting in a force 1640 being applied to cam surface 1416 as shown.

[0058] FIG. 17 illustrates another cam engagement assembly 1700 according to one or more alternative embodiments. In the illustrated example, the cam engagement assembly 1700 is a dual cam engagement assembly having a first cam 1702 and a second cam 1704. The first cam 1702 and the second cam 1704 overlap one another. The first cam 1702 is slidably disposed on the sliding surface 1412 of the hub member 1402. The second cam 1704 is slidably disposed on the outer cam surface 1706 of the first cam 1702. The second cam 1704 has an outer cam surface 1708 that abuts the inner surface of the lower rail 102. Therefore, the first cam 1702 can be referred to as the inner cam, and the second cam 1704 can be referred to as the outer cam. A cam spring force 1710 acts on the first cam 1702. The lower rail 102 and upper rail 104 are moving relative to one another, with the lower rail 102 moving in direction 1712 and the upper rail 104 moving in direction 1714. This movement exerts a force 1720 on the surface of the cam as shown. This force 1720 includes both normal forces and any frictional forces.

[0059] 15B 。 In this example, the slide member 1406 has a flat, angled slide surface 1508 configured to contact the cam surface 1416 of the cam member 1404 at a single contact point 1510. The lower rail 102 and the upper rail 104 are moving relative to one another, with the lower rail 102 moving in a direction 1802 and the upper rail 104 moving in a direction 1804 opposite to direction 1802. This causes a force 1820 to act at the interface between the flat, angled slide surface 1508 and the cam surface 1416, and between the inner surface of the lower rail 102 and the top surface of the slide member 1406.

[0060] 19 illustrates another engagement assembly 1900 according to one or more alternative embodiments. In the illustrated example, the engagement assembly 1900 is a dual wedge engagement assembly having a first wedge 1902 and a second wedge 1904. The first wedge 1902 is biased in a first direction 1906 by a first biasing member 1908, and the second wedge 1904 is biased in a second direction 1910 by a second biasing member 1912. The first biasing member 1908 and the second biasing member 1912 are tension springs. However, as described herein, other types of biasing members may be used without departing from this disclosure. In the illustrated example, the first wedge 1902 has a lower surface 1914 that is slidable on a surface 1916 of the upper rail 104, and the second wedge 1904 has an upper surface 1918 that is slidable on a surface 1920 of the lower rail 102, as described herein. Also, the first wedge 1902 has an upper angled surface 1922, and the second wedge 1904 has a lower angled surface 1924 that abuts and slides against the upper angled surface 1922 of the first wedge 1902, as described herein.

[0061] The present embodiment relates to a seat rail assembly 100 that uses relatively long rails 102 that repeatedly engage slots 118 to drive and support a load. Even when manufactured to tight tolerances, the system can have backlash (e.g., lash, play, or slop) that exceeds customer requirements. A gearbox with a drive screw is used to drive the upper rail 104 within the lower rail 102, and this longitudinal slop can be reduced by modifying the gearbox's internal assembly and how the gearbox's drive screw engages the longitudinal slots 118 in the lower rail 102. Thus, the gearbox includes one or more active lobe mechanisms to eliminate longitudinal play between the drive screw (of the gearbox) and the slots 118 in the lower rail 102. As described herein, the active lobe mechanism is located outside the bearing plates of the gearbox so that longitudinal play between the drive screw and slot 118 is eliminated, thereby eliminating longitudinal play within the gearbox that may exist between the bearing end plates.

[0062] 20 illustrates a gearbox 2000 that can be used to drive the rail assemblies described herein, in accordance with one or more embodiments of the present disclosure. In the illustrated example, the gearbox 2000 is attached to the upper rail 104 and is operable to drive or move the upper rail 104 relative to the lower rail 102. As described below, the gearbox 2000 includes a drive screw and is configured to address or eliminate wobble due to a gap or space between the drive screw and the slot 118 of the lower rail 102.

[0063] The gearbox 2000 includes at least one drive screw 2002, a lobe 2004 associated with each of the at least one drive screws 2002, and a housing 2006 that houses the drive screw 2002 and its associated lobe 2004. As described below, the lobes 2004 are spring-loaded (i.e., are "active lobes") so that they can operate to eliminate clearance between the drive screw 2002 and the slots 118 in the lower rail 102. The housing 2006 has one or more legs 2008 configured to be inserted into corresponding slots (not shown) in the upper rail 104 (not shown). The gearbox 2000 includes an input portion 2010 into which an external drive shaft (not shown) or other external drive source is inserted. The input portion 2010 is rotatably fixed to the drive gear 2012 so as to rotate unitarily therewith. The drive screw 2002 has a shaft (not visible in the figures) around which a threaded portion 2014 extends. Attached to the shaft of the drive screw 2002 is a driven gear 2016, the teeth of which are configured to mesh with the teeth of the drive gear 2012. The driven gear 2016 is rotatably fixed to the shaft of the drive screw so as to rotate therewith. Thus, when the drive gear 2012 is rotated by rotation of the input portion 2010 (e.g., via an external drive shaft), the meshing of the teeth of the drive gear 2012 with the teeth of the driven gear 2016 drives the driven gear 2016, which in turn rotates the shaft of the drive screw 2002 and the threaded portion 2014. Additionally, the lobes 2004 have threads 2020 that abut or contact the threads 2014 of the drive screw 2002 such that rotation of the drive screw 2002 causes the lobes 2004 to rotate.

[0064] The housing 2006 may include multiple housing portions. In the illustrated example, the housing 2006 includes at least a first portion 2022 (e.g., a lower portion or bottom portion) and a second portion 2024 (e.g., a top or lid portion). The housing 2006 holds a pair of bearing plates 2030a, 2030b. The bearing plates 2030a, 2030b rotatably support the shaft of the drive screw 2002, as described below. In the illustrated example, the bearing plate 2030a is disposed between the lobe 2004 and the drive screw 2002. Note that, as described below, in some embodiments, the lobe 2004 may be disposed between the bearing plate 2030a and the drive screw 2002.

[0065] When the gearbox 2000 is assembled to the upper rail 104, the threaded portion 2014 of the drive screw 2002 engages with the slots 118 formed in the left and right inner plate portions 114 of the lower rail 102, thereby causing the upper rail 104 to move relative to the lower rail 102 by the operation (rotation) of the drive screw 2002.

[0066] Figure 21 is an exploded view of another example gearbox 2100 with the top portion 2024 of the housing 2006 removed. Figure 21 also shows the example gearbox 2100 including a pair of drive screws 2002a, 2002b and a corresponding pair of lobes 2004a, 2004b. The base 2022 of the housing 2006 has a pair of wells 2102a, 2012b shaped and sized to receive the drive screws 2002a, 2002b and the corresponding lobes 2004a, 2004b.

[0067] Each of the drive screws 2002a, 2002b has a shaft 2104 with a helical threaded portion 2014 extending thereabout. A driven gear 2016 is attached to a first end (not visible) of the shaft 2104, while an opposite second end 2106 of the shaft 2104 extends beyond the threaded portion 2014. The second end 2106 does not have any helical threads. The lobes 2004a, 2004b have bores 2108 disposed in their corresponding second ends 2106 of the shafts 2104. In this manner, the lobes 2004a, 2004b can freely rotate on their corresponding shafts 2104 relative to their associated drive screws 2002a, 2002b. In the illustrated example, the lobes 2004a, 2004b are free to rotate on their corresponding shafts 2104 relative to their associated drive screws 2002a, 2002b within a limited range of rotation.

[0068] Each lobe 2004a, 2004b is spring biased. In the illustrated example, a lobe spring 2110 is provided in the bore 2108 of each lobe 2004a, 2004b, and the shaft 2104 of the drive screw 2002a, 2002b extends through both the lobe 2004a, 2004b and its corresponding lobe spring 2110. In the illustrated example, the end of each lobe 2004a, 2004b is provided with a boss 2111. The portion of the bore 2108 that extends through the boss 2111 has a slightly larger radius than the remainder of the bore 2108 of the lobe 2004, allowing the lobe spring 2110 to be positioned within the boss 2111 and to receive the end 2106 of the shaft 2104 of the drive screw 2002a, 2002b without interference. As such, the bore 2108 is slightly larger in size at the portion passing through the embossment 2111 to accommodate a lobe spring 2110 having substantially the same bore dimensions as the remainder of the bore passing through the lobes 2004 a, 2004 b. When assembled, each lobe spring 2110 has a pair of spring ends 2112 a, 2112 b configured to engage one of the lobes 2004 a, 2004 b and one of the shafts 2104. Specifically, when assembled, the first spring end 2112 a is retained within a slot or opening 2114 in each lobe 2004 a, 2004 b adjacent the bore 2108, and the second spring end 2112 b is retained / engaged within a slot 2116 in the second end 2106 of each shaft 2104. Lobe spring 2110 applies a rotational spring force to lobes 2004a, 2004b, such that as shaft 2104 rotates, lobe spring 2110 biases lobes 2004a, 2004b about shaft 2104. In this manner, each lobe 2004a, 2004b is biased to rotate about shaft 2104. Each lobe 2004a, 2004b is therefore coupled to its corresponding drive screw 2002a, 2002b via its lobe spring 2110.Each lobe 2004a, 2004b can rotate independently of its corresponding drive screw 2002a, 2002b, but such independent rotation is constrained or limited by a lobe spring 2110 that applies a rotational force to the lobes 2004a, 2004b in response to rotation of the drive screws 2002a, 2002b.

[0069] In the illustrated example, drive screws 2002a, 2002b each include a pressure plate 2118 and a washer 2120, with all components held in place by a bearing plate assembly 2122. In the illustrated example, washer 2120 is a wave washer, and when assembled, one side of pressure plate 2118 contacts the embossments 2111 of lobes 2004a, 2004b, and the other side of pressure plate 2118 contacts wave washer 2120, thereby absorbing the force of wave washer 2120 without contacting lobe spring 2110. Bearing plate assembly 2122 includes a plate 2124 and a pair of rotatable couplings 2126a, 2126b supported by plate 2124. Each of the rotatable couplings 2126a, 2126b is rotatable within the plate 2124 and is configured to receive a respective end 2106 of the shaft 2104. Thus, when assembled, the end 2106 of the shaft 2104 is rotatably supported by the bearing plate assembly 2122. In the exemplary embodiment of FIG. 21 , the bearing plate 2122a is provided on the end 2106 of the shaft 2104 such that the lobes 2004a, 2004b are interposed between the plate 2124 of the bearing plate 2122a and the threaded portion 2014 of the drive screws 2002a, 2002b. However, the bearing plate 2122a may be positioned in another location; for example, the bearing plate 2122a may be positioned such that it is interposed between the threaded portion 2014 and the corresponding lobe 2004a, 2004b. Additionally, bearing plates 2122a, 2122b are retained within slots 2128 formed in housing 2006. Slots 2128 are provided in the upper and lower housing portions 2024, 2022 and are configured to position bearing plate 2122a at the end of shaft 2104 adjacent lobes 2004a, 2004b (i.e., the end opposite threads 2014 of drive screws 2002a, 2002b).

[0070] FIG. 22 illustrates an example of the operation of the drive train of the gearbox 2100 of FIG. 21. Specifically, FIG. 22 shows that each of the lobes 2004a, 2004b is spring-loaded by a lobe spring 2110, such that the lobes 2004a, 2004b are "active" rather than simply free-floating. In the illustrated example, the lobe spring 2110 exerts a torsional spring force on the lobes 2004a, 2004b in a counterclockwise direction about the shaft 2104, as indicated by arrow 2200. The spring-loaded lobes 2004a, 2004b fill the gap in the slot 118 of the lower rail 102, thereby eliminating fore and aft slop.

[0071] This torsional spring force 2200 rotates the corresponding lobe 2204a, 2004b independently of its associated drive screw 2002a, 2002b, thereby effectively increasing the pitch of one of the threads. In other words, the pitch between the active lobe and the last (rearmost) thread of the drive screw increases. Specifically, each lobe spring 2110 increases the width between the thread 2020 of the lobe 2204a, 2004b and the last thread 2202 of the drive screw 2002a, 2002b. The increased width between the last thread 2202 and the thread 2020 of the lobe 2204 closes the gap in the slot 118 of the lower rail 102. In one example, the active lobe maintains a pressure angle that eliminates the chance of backdrive under longitudinal bias. The pressure angle is defined by the interface between the threads of the active lobe and the slot 118 of the lower rail 102. In a particular embodiment, a pressure angle of 7.4 degrees is selected to prevent backdrive under longitudinal bias. The absence of backdrive, combined with the absence of clearance between the threads of the active lobe and the slot 118 of the lower rail 102, results in no longitudinal play.

[0072] FIG. 23 is an end view of the drive train of FIG. 22. Specifically, FIG. 23 illustrates an example configuration of the lobe spring 2110 interacting with the shaft 2104 and its associated lobes 2204a, 2004b. FIGS. 24A and 24B illustrate an example of the operation of the active lobes (i.e., spring-loaded lobes 2004a, 2004b) and their operation to remove slop in the system. Specifically, FIG. 24A illustrates a system in which the lobes 2004 are not spring-loaded (i.e., not active) as described herein, and as a result, a gap (or space) 2400 exists between the threads of the drive screw 2002 and the lobe 2004 and the slot 118 of the lower rail 102 on the same side of the threads. This results in rattle (i.e., slop or play). 24B illustrates how such play is eliminated by operating the lobes 2004, for example, by the lobe spring 2110 exerting a torsional spring force 2200 on the lobes 2004a, 2004b about the shaft 2104, causing the lobes 2004 to move (relative to the shaft 2104 of the drive screw 2002) in the direction indicated by arrow 2402, thereby closing the gap between the lobes 2004 and the slots 118 in the lower rail 102, as indicated by arrow 2404. Thus, the lobes 2004 contact one first side of the slots 118, as indicated by arrow 2404, while the threads of the drive screw 2002 contact the other side of the slots 118, as indicated by arrow 2406, thereby eliminating the slop or play. In this manner, the lobes 2004 a , 2004 b (ie, the active lobes) biased by the spring 2110 eliminate longitudinal play associated with the slot 118 of the lower rail 102 and the threads of the drive screw 2002 .

[0073] The spring-loaded active lobe 2004 rotates, as shown by arrow 2200, until tooth A of the lobe 2004 contacts the opposing tooth wall B of the lower rail 102, thereby eliminating the clearance, as shown by arrow 2404. Teeth C-G of the drive screw 2002 are the threaded portion 2014 of the drive screw 2002, and because the pitch of the threaded portion 2014 of the drive screw 2002 is fixed and uniform, a drive screw 2002 without an active lobe would have longitudinal play equal to the amount of clearance between the threaded portion of the drive screw 2002 and the slot 118 of the lower rail 102. However, the incorporation of lobe tooth A of the lobe 2004, which is spring-loaded by the lobe spring 2110, cooperates with tooth C of the drive screw 2002 to form a wedge, thereby eliminating the play or slop.

[0074] As previously described, rotation of the active lobe 2004 relative to the drive screw 2002 is limited. FIG. 25 illustrates an example of a drive screw 2002 configured to limit rotation of the lobe 2004, according to one or more embodiments. Specifically, while FIG. 25 illustrates one lobe 2004a, it should be understood that the principles described in this figure are also applicable to the other lobe 2004b. Accordingly, this figure will be described with reference to each of the lobes 2004. In the illustrated example, a feature 2502 is provided proximate the end 2106 of the shaft 2104. The feature 2502 is a flat surface formed on the outer periphery of the shaft 2104. The feature 2502 is configured to allow for a limited angle of rotation of the lobe 2004 relative to the shaft 2104. The feature 2502 allows for approximately 10 degrees of relative rotation of the lobe 2004, which is sufficient to eliminate clearance in the system. However, in other examples, feature 2502 may have other dimensions to allow for other degrees of relative rotation of lobes 2004 sufficient to eliminate clearance from the system. As described below, lobe 2004 has a feature within bore 2108 that engages flat feature 2502 when rotated a predetermined angle in either a clockwise or counterclockwise direction.

[0075] 26 and 27 illustrate an example of the operation of the drive train within the gearbox 2100 to remove slop from the system. FIG. 26A illustrates the counterclockwise rotation of the drive gear 2012, as indicated by arrow 2602. The counterclockwise rotation 2602 of the drive gear 2012, through the interaction of the drive gear 2012 and driven gear 2016 described above, results in the clockwise rotation of the driven gear 2016, as indicated by arrow 2604. The clockwise rotation 2604 of the driven gear 2016, as transmitted through the drive shaft 2104 to which the driven gear 2016 is fixed, results in the clockwise rotation 2604 of the drive screws 2002a, 2002b. Thus, the counterclockwise (2602) drive input causes the drive screws 2002a, 2002b to rotate clockwise (2604), moving the upper rail 104 backward along the lower rail 102 in this example. 26B is a close-up view of the active lobes 2004a, 2004b of FIG. 26A, with the active lobes 2004a, 2004b fully engaged or spring-biased by their lobe springs 2110. Rotation 2604 of the drive screws 2002a, 2002b is transferred to the lobes 2004a, 2004b through the lobe springs 2110. The lobe springs 2110 cause the lobes 2004a, 2004b to rotate clockwise (2604), thereby closing the gap between the lobe teeth A and the tooth wall B of the slot 118 in the lower rail 102. Specifically, the rotational drive screw 2002 acts on the lobe spring 2110 by at least the amount of moment applied to it (i.e., the moment decreases as the active lobe 2004 engages / couples with the lower rail 102 or as the lobe spring 2110 approaches its free or unbiased position). The rotational drive screw 2002 acts on the lobe spring 2110 when the lobe spring 2110 is exerting a minimum moment on the active lobe 2004. The minimum moment of the lobe spring 2110 occurs as the lobe spring approaches its free (unbiased) position until the active lobe 2004 contacts the tooth wall of the lower rail slot opposite the tooth wall contacted by the drive screw, eliminating all longitudinal clearance, or until the rotation limiting mechanism stops further rotation of the active lobe 2004.Thus, clockwise rotational motion 2604 of the drive screw 2002 opens a gap between the active lobe 2004 and the slot 118 in the lower rail 102, thereby allowing the system to move with little resistance while the lobe spring 2110 acts to close the gap by urging the lobe 2004 into contact with the lower rail 102. Specifically, as shown in FIG. 26A , when the drive screw 2002 is rotating clockwise, the upper rail moves rearward relative to the lower rail. In the example shown in FIG. 22 , the lobe spring 2110 is biased in a counterclockwise direction as viewed from the end of the drive system including the active lobe 2004. As shown in FIG. 26A , the lobe spring 2110 of the same example is biased in a clockwise direction as viewed from the end of the drive system including the drive gear 2012. In this example, the drive screw 2002 is rotating in the same direction that the lobe spring 2110 is rotatingly biasing the active lobe 2004. Because the second spring end 2112b is retained / engaged in a slot 2116 in the second end 2106 of each shaft 2104, rearward movement of the drive screw shaft 2014 attempts to pull the lobe rearward and out of contact with the opposite tooth wall (shown at 2404 in FIG. 24B ), but at the same time, the lobe spring 2110 rotates the active lobe 2004 further forward from the drive screw to maintain contact with the opposite tooth wall. Because the drive screw does not move the active lobe 2004 further against the opposite tooth wall, no additional friction or drag is introduced into the system.

[0076] 27A illustrates the clockwise rotation of the drive gear 2012, as indicated by arrow 2702. The clockwise rotation 2702 of the drive gear 2012, due to the interaction between the drive gear 2012 and the driven gear 2016 described above, results in the counterclockwise rotation of the driven gear 2016, as indicated by arrow 2704. The counterclockwise rotation 2704 of the driven gear 2016, as transmitted through the drive shaft 2104 to which the driven gear 2016 is fixed, results in the counterclockwise rotation 2704 of the drive screws 2002a, 2002b. Thus, the clockwise (2702) drive input causes the drive screws 2002a, 2002b to rotate counterclockwise (2704), moving the upper rail 104 forward along the lower rail 102, in this example. FIG. 27B is an enlarged view of the active lobes 2004a, 2004b of FIG. 27A, with the active lobes 2004a, 2004b fully engaged or spring-biased by their lobe springs 2110. Rotation 2704 of the drive screws 2002a, 2002b is transferred to the lobes 2004a, 2004b via the lobe springs 2110. The lobe springs 2110 rotate the lobes 2004a, 2004b clockwise (2702), thereby closing the gap between the lobe teeth A and the tooth wall B of the slot 118 in the lower rail 102. Specifically, the rotational drive screw 2002 acts on the lobe springs 2110 by at least the amount of the moment applied thereto (e.g., the moment decreases as the active lobes 2004 mesh / couple with the lower rail 102). Thus, the counterclockwise rotational movement 2704 of the drive screw 2002 tends to close the gap between the active lobe 2004 and the slot 118 in the lower rail 102, thereby adding frictional drag to the system. In other words, the drive screw 2002 may rotate in a rotational direction opposite to the rotational direction in which the lobe spring 2110 is rotationally biasing the active lobe 2004.Because the second spring ends 2112b are retained / engaged in slots 2116 in the second ends 2106 of each shaft 2104, forward movement of the drive screw shaft 2014 pushes the lobes forward into contact with the opposite tooth wall (shown at 2404 in FIG. 24B ), while the lobe springs 2110 simultaneously rotate the active lobes forward. The drive screw 2002 moves the active lobe 2004 toward the opposite tooth wall while the lobe springs 2110 simultaneously urge the active lobe 2004 into contact with the opposite tooth wall, creating additional friction or drag in the system. Note that the spring constant of the lobe springs 2110 is selected to prevent the system from meshing / binding when the lobe tooth A is urged into contact with the wall of the slot 118 in the lower rail 102. Additionally, the inclusion of wave washer 2120 can further reduce the system's ability to bite / bind.

[0077] 28A and 28B show an example of a lobe 2004 in accordance with one or more embodiments of the present disclosure. In the example shown, a rotation-limiting feature 2802 is formed within the bore 2108 of the lobe 2004. The rotation-limiting feature 2802 is a pair of angled flats 2804, 2806. As described above, rotation of the lobe 2004 about the shaft 2104 is limited by a flat feature 2502 on the shaft 2104 of the drive screw 2002. As the lobe 2004 rotates clockwise or counterclockwise, one of the pair of angled flats 2804, 2806 contacts the flat 2502 on the shaft 2104, thereby preventing further rotation in that direction. The lobe 2004 can then rotate in the opposite direction about the shaft 2104 until the other of the pair of angled flats 2804, 2806 contacts the flat 2502, thereby preventing further rotation in that opposite direction. In this manner, the lobe 2004 can rotate relative to the shaft 2104 at an angle that depends on the angle of the angled flats 2804, 2806. For example, if the angled flats 2804, 2806 were provided without being angled relative to each other so as to extend along the horizontal H, they would always contact the flat feature 2502 of the shaft 2104, thereby defining a flat surface that would prevent any rotation of the lobe 2004. On the other hand, if the angled flats 2804, 2806 are angled relative to one another, only one of the angled flats 2804, 2806 will contact the flat 2502 of the shaft 2104 at a given time, thereby allowing the lobe 2004 to rotate in a predetermined direction until the other of the angled flats 2804, 2806 contacts the flat 2502 of the shaft 2104. FIG. 28B shows the angled flats 2804, 2806 angled at an obtuse angle, which allows for an amount of relative rotation between the lobe 2004 and the shaft 2104. It should be noted that the amount of relative rotation between the lobe 2004 and the shaft 2104 can be increased by reducing such angle, for example, by orienting the angled flats 2804, 2806 at an acute angle.Also, in the illustrated example, each of the angled flats 2804, 2806 is oriented at a predetermined angle with respect to the horizontal H. Flat 2804 is oriented at an angle φ with respect to the horizontal H, and flat 2806 is oriented at an angle φ' with respect to the horizontal H. In the illustrated example, angles φ and φ' are each 10 degrees, allowing lobe 2004 to rotate 10 degrees in either a clockwise or counterclockwise direction about shaft 2104 until one of angled flats 2804, 2806 contacts flat 2502 of shaft 2104. However, other angle values ​​can be selected to provide greater or lesser amounts of relative rotation, as desired.

[0078] 28A and 28B also illustrate an example of a method for installing a lobe spring (not shown) in the lobe 2004. In the example shown, an embossment 2111 projects outward from the surface 2808 of the lobe 2004, thereby defining a spring pocket 2810 within which the lobe spring can be installed. When assembled, the lobe spring 2110 is positioned on the surface 2808 of the lobe 2004, with the first spring end 2112a extending through the opening 2114 in the embossment 2111.

[0079] FIG. 29 illustrates another gearbox 2900 that can be used to drive the seat rail assemblies described herein. The gearbox 2900 is configured to address or eliminate rattle (i.e., lash, play, or slop) caused by a gap or space between the drive screw and the slot in the lower rail. Additionally, the gearbox 2900 is configured to address or eliminate rattle due to a gap or space between the drive screw and a bearing plate. FIG. 30 is a side cross-sectional view of the gearbox 2900 of FIG. 29. FIG. 31 is an exploded view of the gearbox 2900 of FIG. 29. The gearbox 2900 is similar to the gearbox 2100 described above, except that a bearing plate 2900a is positioned between the drive screw 2002 and the lobe 2004. As shown, the housing is configured to hold the bearing plate 2122a in an intermediate position between the drive screw 2002 and the lobe 2004. In the illustrated example, slots 3102 are provided in the base 2022 of the housing 2006 to hold the bearing plate 2122a in a desired position between the drive screw 2002 and the lobes 2004. Although not shown, the top 2024 of the housing 2006 has corresponding slots to hold the bearing plate 2122a in a desired position when assembled. In this design, the lobes 2004a, 2004b become active lobes when subjected to the biasing force of the lobe spring 2110, and similar to the gearbox 2100 described above, the active lobes 2004a, 2004b directly interact with the shafts 2104 of the drive screws 2002a, 2002b. However, because bearing plate 2122a is located between lobes 2004a, 2004b and the threads of drive screws 2002a, 2002b, bearing plate 2122a isolates lobes 2004a, 2004b from the longitudinal action of drive screws 2002a, 2002b.

[0080] FIG. 32 illustrates an example of the operation of the drive train of the gearbox 2900 of FIG. 31. Specifically, FIG. 32 shows that each of the lobes 2004a, 2004b is spring-loaded by a lobe spring 2110, such that the lobes 2004a, 2004b are "active" rather than simply free-floating. In the illustrated example, the lobe spring 2110 exerts a torsional spring force on the lobes 2004a, 2004b in a clockwise direction about the shaft 2104, as indicated by arrow 3202. The spring-loaded lobes 2004a, 2004b fill the gap in the slot 118 of the lower rail 102, thereby eliminating fore and aft slop.

[0081] FIG. 33 is a partial cross-sectional view illustrating an example operation of the gearbox 2900. In this design, the load case with the bearing plate assembly 2122 eliminates the wave washer 2120 loading scenario described above with reference to FIG. 24B, thereby resulting in a true zero-play design. The gearbox 2100 can still have longitudinal play. As shown in FIG. 21, the gearbox 2100 includes an active lobe 2004 located between the drive screw 2002 and the bearing plate 2122a. The active lobe 2004 in this example eliminates longitudinal clearance between the drive screw 2002 and the slot 118 in the lower rail 102. However, because the bearing plates 2122a, 2022b are secured to the gearbox 2100, which houses the top cover 2024 and bottom cover 2022, via the engagement slots 2128, there may be longitudinal clearance between the drive screw 2002 and the bearing plates 2122a, 2022b, which may result in longitudinal play within the gearbox 2100. In other words, when the active lobe 2004 is positioned between the bearing plates 2122a, 2022b, the play between the drive screw 2002 and the slot 118 in the lower rail 102 is eliminated, but the drive train still has the ability to slide longitudinally within the gearbox by an amount equal to the amount of clearance between the drive screw 2002 and the bearing plates 2122a, 2022b. Thus, the gearbox 2900 solves the problem of longitudinal play that may exist or develop within the gearbox by positioning the bearing plate 2122a between the active lobe 2004 and the drive screw 2002. By securing the drive train assembly to one of the bearing plates (i.e., end plates), clearance between the drive screw 2002 and the slot 118 in the lower rail 102 is eliminated, as well as clearance within the gearbox assembly that may exist between the drive screw and the bearing plate.

[0082] It should be understood that multiple active lobes may be included in any position relative to the bearing plates and drive screw. The active lobes may be located on the outside or inside of each bearing plate. Alternatively, a first active lobe may be located on the outside of the first bearing plate and a second active lobe may be located on the inside of the second bearing plate. Alternatively, a first active lobe may be located on the outside of the first bearing plate and a second active lobe may be located on the inside of the first bearing plate.

[0083] 34 and 35 show an example of the operation of the drive train within the gearbox 2900 to remove slop from the system. As shown in FIG. 34A, a counterclockwise drive input causes the drive screws 2002a, 2002b to rotate clockwise, as indicated by arrow 3402, moving the upper rail 104 backward along the lower rail 102 in this example. As shown in FIG. 34B, the rotating drive screws 2002a, 2002b act on the lobe springs 2110 by at least the amount of moment applied to them (i.e., the moment decreases as the active lobes 2004a, 2004b mesh / couple with the lower rail 102). The rotational movement of the drive screws is always in a direction that closes the gap between the active lobes 2004a, 2004b and the slots 118 in the lower rail 102, thereby adding frictional drag to the system. However, the system does not bind because the wave washers 2120 within the system are compressed, allowing the drive screw 2002 to continue its movement. Referring to FIGS. 35A and 35B, when a clockwise driving force is input through the shaft, the drive screws 2002a, 2002b rotate counterclockwise, as indicated by arrow 3502, causing the upper rail 104 to move forward relative to the lower rail 102. As shown in FIG. 35B, the rotating drive screws 2002a, 2002b act on the lobe springs 2110 by at least the amount of moment applied thereto (e.g., the moment decreases as the active lobes 2004a, 2004b mesh / couple with the lower rail 102). The rotational movement of the drive screws opens a gap between the active lobes 2004a, 2004b and the walls of the slot 118 in the lower rail 102, allowing the system to move with little resistance.

[0084] Thus, the systems and methods of the present disclosure are well adapted to achieve the objects and advantages mentioned, as well as those inherent therein. The specific embodiments disclosed above are illustrative only, and the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of this disclosure. Furthermore, no limitations are intended with respect to the details of construction or design shown, other than as set forth in the following claims. It is therefore apparent that the specific exemplary embodiments disclosed above may be changed, combined, or modified, and all such variations are considered to be within the scope of the present disclosure. The illustratively disclosed systems and methods may be practiced in the absence of any element not specifically disclosed herein and / or any element disclosed herein. Terms in the claims have their plain and ordinary meaning unless expressly and unambiguously defined by the patentee. All numerical values ​​set forth herein are for the specific embodiment described and may be modified appropriately for a given application. The indefinite article "a" or "an" used in the claims refers to one or more of the corresponding element. If there is a conflict in the usage of a word or term in this specification and one or more patents or other documents incorporated herein by reference, the consistent definition in this specification shall control.

[0085] The use of directional terms such as up, down, upper, lower, above, below, left, right, etc. are used in connection with the illustrated embodiments and as shown in the figures, with the up or upper direction being toward the top of the corresponding figure and the down or lower direction being toward the bottom of the corresponding figure.

[0086] As used herein, the phrase "at least one" preceding a list of items, with the term "and" or "or" separating any items, modifies the list as a whole, rather than each individual member (i.e., each item) of the list. The phrase "at least one" allows for inclusion of at least one of any item, and / or at least one of any combination of items, and / or at least one of each item. By way of example, the phrases "at least one of A, B, and C" or "at least one of A, B, or C" refer to A only, B only, C only, any combination of A, B, and C, and / or at least one of A, B, and C, respectively.

Claims

[Claim 1] 1. A seat rail assembly for mounting at least one vehicle seat, comprising: a lower rail configured to be attached to a vehicle floor, the lower rail defining a sliding space; an upper rail configured to support at least one vehicle seat mounted thereon, at least a portion of which is disposed within the sliding space of the lower rail and is slidable relative to the lower rail in a first direction or a second direction opposite to the first direction; an engagement assembly provided in the sliding space of the lower rail, the engagement assembly including a lower engagement member and an upper engagement member configured to move independently of each other in response to movement of the upper rail relative to the lower rail, the lower engagement member being slidably provided on the upper rail, and the upper engagement member being slidably provided on the lower engagement member between a first position and a second position; The lower engagement member is biased in the first direction, the upper engagement member is biased in the second direction toward the first position; When the upper rail slides relative to the lower rail in the first direction or the second direction, the upper engagement member maintains contact with the lower rail and the lower engagement member maintains contact with the upper rail.

Images