Low profile seat track system

A seat track system for a seat of a vehicle includes at least one seat track having a lower track member adapted to be fixed to a vehicle structure and an upper track member adapted to be connected to a seat and moveable relative to the lower track member. The seat track system also includes a manual positive engagement locking system cooperating with the at least one seat track to allow longitudinal adjustment of the upper track member relative to the lower track member and to positively engage the at least one seat track such that a locking element does extend through the locking plate but does not extend below the lower track member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to seats for vehicles and, more specifically, to a seat track system with a low profile track and manual positive engagement locking mechanism for a seat of an automotive vehicle.

2. Description of the Related Art

It is known to provide a seat for a vehicle such as an automotive vehicle. Typically, the seat includes a generally horizontal seat portion and a generally vertical back portion operatively connected to the seat portion. The seat may include at least one, preferably a pair of tracks to allow horizontal adjustment of the seat portion and a pivoting mechanism to allow vertical adjustment of the seat portion. The tracks are spaced laterally and extend longitudinally and are secured to vehicle structure such as a seat riser by suitable means such as fasteners. The tracks are steel, rolled sections with a fixed lower track member and a sliding upper track member. The tracks may be longitudinally adjusted manually or by power. The longitudinal adjustment of the vehicle seat, in some applications, must include positive or continuous engagement in any position with the track to prevent longitudinal movement of the seat during a vehicle impact.

Therefore, it is desirable to provide a seat track system for a seat of a vehicle that provides a positive engagement to prevent movement of the seat once it is adjusted. It is also desirable to provide a seat track system for a seat of a vehicle that has a very low track profile. It is further desirable to provide a seat track system for a seat of a vehicle that has a positive engagement locking mechanism capable of operating in a very low track profile. Thus, there is a need in the art to provide a seat track system that meets at least one of these desires.

SUMMARY OF THE INVENTION

It is, therefore, one object of the present invention to provide a new seat track system for a seat of a vehicle.

It is another object of the present invention to provide a low profile track in a seat track system for a seat of a vehicle.

It is yet another object of the present invention to provide a positive engagement locking system for a seat track system for a seat of a vehicle.

It is still another object of the present invention to provide a locking mechanism for a seat track system which can lock up at any arbitrary seat slide position with minimal play between locking elements and lock apertures provided in a locking member.

To achieve one or more of the foregoing objects, the present invention is a manual positive engagement locking mechanism for a seat track system for a seat of a vehicle. The manual positive engagement locking mechanism includes a locking member disposed between a lower track member adapted to be fixed to a vehicle structure and an upper track member adapted to be connected to a seat and moveable relative to the lower track member. The manual positive engagement locking mechanism also includes at least one movable locking element selectively engagable and disengageable with the locking member to allow a position of the seat to be adjusted longitudinally and to prevent the position of the seat from moving once the position has been adjusted.

The present invention is also a low profile seat track for a seat of a vehicle. The low profile seat track includes a lower track member adapted to be fixed to a vehicle structure and an upper track member adapted to be connected to a seat and moveable relative to the lower track member. The lower track member has a general U shape with outer flanges extending downwardly. The upper track member has a general U shape with inner flanges extending upwardly such that the outer flanges overlap the inner flanges to give the seat track a vertical height less than 30 millimeters.

Additionally, the present invention is a seat track system for a seat of a vehicle. The seat track system includes at least one seat track having a lower track member adapted to be fixed to a vehicle structure and an upper track member adapted to be connected to a seat and moveable relative to the lower track member. The seat track system also includes a manual positive engagement locking system cooperating with the at least one seat track to allow longitudinal adjustment of the upper track member relative to the lower track member and to positively engage the at least one seat track such that a locking element does extend through the lower track member.

One advantage of the present invention is that a new seat track system is provided for a seat of a vehicle that prevents longitudinal movement of the seat after adjustment. Another advantage of the present invention is that the seat track system prevents longitudinal movement of the seat once adjusted by positive engagement. Yet another advantage of the present invention is that the seat track system has a mechanical positive engagement locking system that prevents longitudinal movement once the seat is adjusted. Still another advantage of the present invention is that the seat track system has a seat track with a very low track profile. Yet a further advantage of the present invention is that the seat track system has a positive engagement locking mechanism capable of operating in a very low track profile. Still a further advantage of the present invention is that the seat track system has a locking mechanism that can lock up at any arbitrary seat slide position with minimal play between locking pins and the lock apertures provided in a locking member.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings, and in particularFIGS. 1 through 7, one embodiment of a seat track system10, according to the present invention, is shown for adjusting a longitudinal position of a seat11(FIG. 1) in a vehicle (not shown) such as an automotive vehicle. The seat track system10includes at least one or more low profile seat rails or tracks, generally indicated at12, interconnecting the seat11and a floor (not shown) of the vehicle. As illustrated, the seat track12extends longitudinally. The seat track12includes a lower track member14. The lower track member14has a lower base portion16extending laterally and a pair of side portions18extending upwardly from the sides of the base portion16to form a generally “U” shape. The lower track member14has an upper flange20extending laterally inward from each side portion18and a side flange22extending downwardly from each upper flange20to form a generally inverted “U” shape. The lower track member14is connected to a seat riser (not shown) of the floor. It should be appreciated that there are two seat tracks12per seat11and that the lower track member14is attached to an outboard and inboard seat riser.

Each seat track12also includes an upper track member28to slide along the lower track member14. The upper track member28has an upper base portion30extending laterally and a pair of side portions32extending downwardly from the sides of the base portion30to form a generally inverted “U” shape. The upper track member28also has a lower flange34at each lower end of the side portions32extending laterally outwardly. The upper track member28has a second flange36extending arcuately upwardly from the first flange30in a convex manner and a third flange38extending arcuately upwardly from the second flange36in a concave manner. The track members14and28are made of a rigid material such as metal. The upper track member28is connected to a seat pan (not shown) of the seat11.

The track members14and28have a predetermined wall thickness of approximately 1.8-2 millimeters. The lower track member14has a vertical height from the outer surface of the base portion16to the outer surface of the upper flange20of approximately 19 millimeters. The upper track member28has a vertical height from the outer surface of the base portion16to the outer surface of the base portion30of approximately 30 millimeters. It should be appreciated that the seat tracks12have a low profile because locking elements to be described do not extend through the lower track member14. It should also be appreciated that the lower track member14is fixed and the upper track member28may be moved by a suitable mechanism to be described.

The seat track system10also includes one or more first rollers40and spacers41disposed in the space between the second flange36and the corner between the base portion16and side portions18of the lower track member14. The rollers are generally spherical in shape and the spacers41are generally cylindrical in shape. The rollers40and spacers41are spaced longitudinally between the track members14and28. The rollers40contact the interior surface of the lower track member14and the outer surface of the upper track member28. The seat track system10also includes one or more second rollers42and spacers43disposed in the space between the third flange38and the corner between the upper flange20and the side flange22of the lower track member14. The rollers42are generally spherical in shape and the spacers43are generally cylindrical in shape, both being spaced longitudinally between the track members14and28. The rollers42contact the interior surface of the lower track member14and the interior surface of the upper track member28. It should be appreciated that the rollers40and42allow the upper track member28to slide on the lower track member14with minimal friction.

The seat track system10includes a locking member or bracket44extending longitudinally and disposed within the lower track member14. The locking member44has an upper base portion46extending laterally and a pair of side portions48extending downwardly from the sides of the base portion46to form a generally inverted “U” shape. The base portion46has a plurality of apertures50extending therethrough and spaced longitudinally. The locking member44is made of a rigid material such as metal. The locking member44is connected to the lower track member14by a suitable mechanism such as welding.

The seat track system10may include a front hook attachment52secured to the bottom of the lower track member14by a suitable mechanism such as welding for engaging the seat riser (not shown). The seat track system10may also include a distance plate54attached to the lower track member14by a suitable mechanism such as a rivet56and a locating pin58. It should be appreciated that the front hook attachment52, distance plate54, rivet56, and locating pin58are conventional and known in the art.

The seat track system10may include a forward linkage bracket60attached to a forward end of the upper track member28and a rearward linkage bracket62attached to a rearward end of the upper track member28by a suitable mechanism such as welding. The seat track system10may include a reinforcement bracket64disposed within the rearward end of the upper track member28and a belt buckle bracket66mounted to the upper track member28opposite the reinforcement bracket and rearward of the rearward linkage bracket62. The seat track system10includes a plurality of rivets68for securing the reinforcement bracket64, belt buckle bracket66, and upper track member28together as a single unit. It should be appreciated that the linkage brackets60,62and belt buckle bracket66are conventional and known in the art.

The seat track system10includes a cross tube attachment bracket70secured to the upper track member28by a suitable mechanism such as welding. The cross tube attachment bracket70has an aperture72extending therethrough. The seat track system10also includes a bearing bushing74extending through the aperture72in the cross tube attachment bracket70.

The seat track system10includes a release mechanism, generally indicated at76, for releasing and moving the upper track member28relative to the lower track member14. The release mechanism76includes an actuation lever78extending longitudinally. The release mechanism76has a handle80at a forward end and an end cap82at the rearward end of the actuation lever78. The handle80and end cap82are made of a plastic material. The release mechanism76also includes a cross tube84having one end attached to the actuation lever78and the other end attached to the bushing74. As illustrated, the release mechanism76is a pivotal lever having a handle. It should be appreciated that the release mechanism76, although illustrated as a lever, may be push rods for Bowden cable or a bar as is conventional and known in the art. It should also be appreciated that the release mechanism76is operated by an operator grasping the handle80and rotating the actuation lever78via the cross tube84. It should further be appreciated that the release mechanism76is conventional and known in the art.

The seat track system10includes a positive engagement locking mechanism, generally indicated at86, to lock the upper track member28to the locking member44. The locking mechanism86includes a plurality of locking elements such as locking pins88extending vertically and through the apertures of the locking member44. In the embodiment illustrated, three locking pins88are used to engage two apertures50in the locking member44. Each locking pin88is generally cylindrical in shape and has a frustoconical lower end90to engage the apertures50in the locking member44. Each locking pin88also has a flange92extending radially outwardly a distance spaced from the lower end90to act as a spring seat for a spring to be described. Each locking pin88is made of a metal material such as steel. Two of the locking pins88engage the base portion46through the apertures50of the locking member44for a function to be described. It should be appreciated that the positive engagement locking system86provides positive or continuous engagement in any position of the upper track member28to the lower track member14, wherein for any position of the seat11, the upper track member28is secured to the lower track member14. It should also be appreciated that in every position of the upper track member28, one locking pin88of the locking system86will always fall into one of the apertures50of the lower track member14. It should further be appreciated that the upper track member28can only move relative to the lower track member14until the locking pin88hits the edge of the aperture50, at that point, the second locking pin88engages the locking member44and eliminates the free-play.

The locking mechanism86also includes a guide bracket94to guide the locking pins88into engagement with the locking member44. The guide bracket94extends longitudinally and has a base portion96and a pair of side portions98extending upwardly from the sides of the base portion96to form a generally “U” shape. The guide bracket94has a plurality of guide apertures100extending therethrough and spaced longitudinally for the locking pins88. As illustrated, the guide bracket94has three guide apertures100, one guide aperture100for each locking pin88. The guide bracket94is made of a metal material such as steel.

The locking mechanism86includes a spacer102disposed on the base portion30of the upper track member28. The spacer102has a plurality of guide apertures103extending therethrough and spaced longitudinally for the locking pins88. The spacer102is generally rectangular in shape and has a predetermined thickness. The spacer102is made of a metal material.

The locking mechanism86also includes a cover plate104disposed on the spacer102. The cover plate104is generally “C” shaped. The cover plate104includes a plurality of apertures106extending therethrough and corresponding to the number of locking pins88. The locking mechanism86further includes one or more rivets110extending through the cover plate104, spacer102, and base portion30of the upper track member28to secure the cover plate104, spacer102, and upper track member28together as a unit.

The locking mechanism86includes a plurality of sleeves108disposed on the cover plate104. One sleeve108is located over one of the apertures106. The sleeves108are secured to the cover plate104by a suitable mechanism such as welding.

The locking mechanism86also includes a plurality of springs112for the locking pins88. One spring112is disposed over one locking pin88and has one end that engages the flange92of the locking pin88and another end that engages the sleeve108. The springs112are compression springs.

The locking mechanism86further includes an actuation member114to move the locking pins88. The actuation member114includes a plurality of fingers116extending outwardly. The fingers116are disposed between the locking pins88and engage the flanges92of the locking pins88to move them upwardly against the springs112. The actuation member114has a main portion118extending upwardly from the fingers116. The main portion118is pivotally attached to the cover plate104by a suitable mechanism such as a rod119. The actuation member114has a flange portion120extending outwardly from the main portion118to engage the release mechanism76.

The locking mechanism86also includes a wire spring122for urging the fingers116in a non-engaged position with the flanges92of the locking pins88. The wire spring122has a configuration such that one end engages the guide bracket94and the other end engages the flange portion120of the actuation member114to urge the flange portion120upwardly such that the fingers116do not engage the flanges92of the locking pins88.

Referring toFIGS. 1 through 7, the seat track system10is in an engaged position. As illustrated, two of the locking pins88engage two of the apertures50in the locking member44. In this position, the locking mechanism86provides positive or continuous engagement of the upper track member28to the lower track member14and the upper track member28is secured to the lower track member14.

To move the seat longitudinally, the release mechanism76is operated by an operator grasping the handle80and rotating the actuation lever78via the cross tube84. When this occurs, the actuation member114is rotated such that the fingers116between the locking pins88engage the flanges92of the locking pins88to move them upwardly against the springs112to exit the apertures50in the locking member44. The upper track member28may then be moved longitudinally relative to the lower track member14.

Once the seat is moved to a new position, the release mechanism76is released by the operator. On the return motion of the actuation lever78being released, this return motion causes the actuation member114to rotate due to the wire spring122such that the fingers116between the locking pins88disengage the flanges92of the locking pins88and the springs112move the locking pins88downwardly. When this occurs, one locking pin88will fall into one of the apertures50of the lower track member14and the second locking pin88engages the locking member44to secure the upper track member28to the lower track member14.

Referring toFIGS. 8 through 13, another embodiment210, according to the present invention, of the seat track system10is shown. Like parts of the seat track system10have, like reference numerals increased by two hundred (200). In this embodiment, the seat track system210includes the lower track member214, upper track member228, and locking member244. The seat track system210may also include front hook attachment252, distance plate254, rivet256, and locating pin258. The seat track system210includes the forward linkage bracket260, rearward linkage bracket262, reinforcement bracket264, belt buckle bracket266, and rivets268. The seat track system210includes the cross tube attachment bracket270, bearing bushing274, and release mechanism276. The release mechanism276includes the actuation lever278, handle280, end cap282, and cross tube284.

The seat track system210also includes a positive engagement locking mechanism, generally indicated at286, to lock the upper track member228to the locking member244. The locking mechanism286includes a plurality of locking elements such as locking pins288extending vertically and through the apertures250of the locking member244. In the embodiment illustrated, four locking pins288are used to engage two apertures250in the locking member244. Each locking pin288is generally cylindrical in shape and has a frustoconical lower end290to engage the apertures250in the locking member244. Each locking pin288also has a flange292extending radially outwardly a distance spaced from the lower end290to act as a spring seat for a spring to be described. Each locking pin288is made of a metal material such as steel. Two of the locking pins288engage the base portion246through the apertures250of the locking member244for a function to be described. It should be appreciated that a positive locking system provides positive or continuous engagement in any position of the upper track member228to the lower track member214, wherein for any position of the seat, the upper track member228is secured to the lower track member214. It should also be appreciated that in every position of the upper track member228, one locking pin288of the locking system286will always fall into one of the apertures250of the lower track member214. It should further be appreciated that the upper track member228can only move relative to the lower track member214until the locking pin288hits the edge of the aperture250, at that point, the second locking pin288engages the locking member244and eliminates the free-play.

The locking mechanism286also includes a locking pin guide arm294to guide the locking pins288into engagement with the locking member244. The locking pin guide arm294extends longitudinally and is generally rectangular in shape. The locking pin guide arm294extends longitudinally and has a base portion296and a pair of side portions298extending longitudinally from the sides of the base portion296. The locking pin guide arm294has a plurality of guide apertures300extending therethrough and spaced longitudinally for the locking pins288. As illustrated, the locking pin guide arm294has four guide apertures300, one guide aperture300for each locking pin288. The guide bracket294is made of a metal material such as steel. The locking pin guide arm294is disposed within the upper track member228and secured to the upper track member228by a suitable mechanism such as rivets310extending through apertures in the side portions298.

The locking mechanism286includes a spacer302disposed on the base portion230of the upper track member228. The spacer302has a plurality of guide apertures303extending therethrough and spaced longitudinally for the locking pins288. The spacer302is generally rectangular in shape and has a predetermined thickness. The spacer302is made of a metal material.

The locking mechanism286also includes a cover plate304disposed on the spacer302. The cover plate304is generally “C” shaped. The cover plate304includes a plurality of apertures306extending therethrough and corresponding to the number of locking pins288. The locking mechanism286further includes one or more rivets310extending through the cover plate304, spacer302, and base portion230of the upper track member228to secure the cover plate304, spacer302, and upper track member228together as a unit.

The locking mechanism286includes a plurality of sleeves308disposed on the cover plate304. One sleeve308is located over one of the apertures306. The sleeves308are secured to the cover plate304by a suitable mechanism such as welding.

The locking mechanism286also includes a plurality of springs312for the locking pins288. One spring312is disposed over one locking pin288and has one end that engages the flange292of the locking pin288and another end that engages the sleeve308. The springs312are compression springs.

The locking mechanism286further includes an actuation member314to move the locking pins288. The actuation member314includes a plurality of fingers316extending outwardly. The fingers316are disposed between the locking pins288and engage the flanges292of the locking pins288to move them upwardly against the springs312. The actuation member314has a main portion318extending upwardly from the fingers316. The main portion318is pivotally attached to the cover plate304by a suitable mechanism such as a rod319. The actuation member314has a flange portion320extending outwardly from the main portion318to engage the release mechanism276.

The locking mechanism286also includes a wire spring322for urging the fingers316in a non-engaged position with the flanges292of the locking pins288. The wire spring322has a configuration such that one end engages the guide bracket294and the other end engages the flange portion320of the actuation member314to urge the flange portion320upwardly such that the fingers316do not engage the flanges292of the locking pins288.

Referring toFIGS. 8 through 13, the seat track system210is in an engaged position. As illustrated, two of the locking pins288engage two of the apertures250in the locking member244. In this position, the locking mechanism286provides positive or continuous engagement of the upper track member228to the lower track member214and the upper track member228is secured to the lower track member214.

To move the seat longitudinally, the release mechanism276is operated by an operator grasping the handle280and rotating the actuation lever278via the cross tube284. When this occurs, the actuation member314is rotated such that the fingers316between the locking pins288engage the flanges292of the locking pins288to move them upwardly against the springs312to exit the apertures250in the locking member244. The upper track member228may then be moved longitudinally relative to the lower track member214.

Once the seat is moved to a new position, the release mechanism276is released by the operator. On the return motion of the actuation lever278being released, this return motion causes the actuation member314to rotate due to the wire spring322such that the fingers316between the locking pins288disengage the flanges292of the locking pins288and the springs312move the locking pins288downwardly. When this occurs, one locking pin288will fall into one of the apertures250of the lower track member214and the second locking pin288engages the locking member244to secure the upper track member228to the lower track member214.

Referring toFIGS. 14 through 19, yet another embodiment410, according to the present invention, of the seat track system10is shown. Like parts of the seat track system10have like reference numerals increased by four hundred (400). In this embodiment, the seat track system410includes the lower track member414, upper track member428, and locking member444. The seat track system410may also include front hook attachment452, distance plate454, rivet456, and locating pin458. The seat track system410includes the forward linkage bracket460, rearward linkage bracket462, reinforcement bracket464, belt buckle bracket466, and rivets468. The seat track system410further includes the cross tube attachment bracket470, bearing bushing474, and release mechanism476. The release mechanism476includes the actuation lever478, handle480, end cap482, and cross tube484.

The seat track system410also includes a positive engagement locking mechanism, generally indicated at486, to lock the upper track member428to the locking member444. The locking mechanism486includes a plurality of locking elements such as locking pins488extending vertically and through the apertures450of the locking member444. In the embodiment illustrated, three locking pins488are used to engage, two apertures450in the locking member444. Each locking pin488is generally cylindrical in shape and has a frustoconical lower end490to engage the apertures450in the locking member444. Each locking pin488also has a flange492extending radially outwardly a distance spaced from the lower end490to act as a spring seat for a spring to be described. Each locking pin488is made of a metal material such as steel. Two of the locking pins488engage the base portion446through the apertures450of the locking member444for a function to be described. It should be appreciated that a positive locking system provides positive or continuous engagement in any position of the upper track member428to the lower track member414, wherein for any position of the seat, the upper track member428is secured to the lower track member414. It should also be appreciated that in every position of the upper track member428, one locking pin488of the locking system486will always fall into one of the apertures450of the lower track member414. It should further be appreciated that the upper track member428can only move relative to the lower track member414until the locking pin488hits the edge of the aperture450, at that point, the second locking pin488engages the locking member444and eliminates the free-play.

The locking mechanism486also includes a locking pin guide arm494to guide the locking pins488into engagement with the locking member444. The locking pin guide arm494extends longitudinally and is generally rectangular in shape. The locking pin guide arm494extends longitudinally and has a base portion496and a pair of side portions498extending longitudinally from the sides of the base portion496. The locking pin guide arm494has a plurality of guide apertures500extending therethrough and spaced longitudinally for the locking pins488. As illustrated, the locking pin guide arm494has three guide apertures500, one guide aperture500for each locking pin488. The guide bracket494is made of a metal material such as steel. The locking pin guide arm494is disposed within the upper track member428and secured to the upper track member428by a suitable mechanism such as rivets extending through apertures in the side portions498.

The locking mechanism486includes a spring housing501disposed on the base portion430of the upper track member428. The spring housing501extends longitudinally and is generally rectangular in shape. The spring housing501has a plurality of spring cavities503. As illustrated, the spring housing501has three spring cavities503, one spring cavity503for each locking pin488. The spring housing501is made of a metal material such as steel.

The locking mechanism486includes a cover plate504disposed over the spring housing501. The cover plate504extends longitudinally and is generally rectangular in shape. The cover plate504has a main portion505and a pair of side portions506extending downwardly from the sides of the main portion505. The cover plate504is generally “U” shaped. The cover plate504is attached to the spring housing501by a suitable mechanism.

The locking mechanism486also includes a plurality of pressure springs512for the locking pins488. One pressure spring512is disposed over one locking pin488and has one end that engages the flange492of the locking pin488and another end that engages the spring housing501. The pressure springs512are compression springs.

The locking mechanism486includes a bearing pin housing530disposed over the cover plate504and mounted to the upper track member428. The bearing pin housing530extends longitudinally and is generally rectangular in shape. The bearing pin housing530has an upper base portion532and a pair of side portions534extending downwardly from the sides of the base portion532. The bearing pin housing530has a flange portion536extending longitudinally from each side portion534. The flange portion536has an aperture538extending therethrough. It should be appreciated that the rivets510previously described extend through the apertures538in the flange portions536to secure the bearing pin housing530to the upper track member428.

The locking mechanism486also includes a distance bushing540secured to each of the side portions534. The locking mechanism486includes a bearing bolt542extending through the distance bushings540. The locking mechanism486includes a leg or wire spring522having a configuration such that one end engages the bearing pin housing530and the other end engages the bearing bolt542. It should be appreciated that the bearing bolt542is rotatable in the distance bushings540.

The locking mechanism486further includes an actuation member514such as an unlocking damper to move the locking pins488. The actuation member514includes a plurality of fingers516extending outwardly. The fingers516are disposed between the locking pins488and engage the flanges492of the locking pins488to move them upwardly against the springs512. The actuation member514has a main portion518extending upwardly from the fingers516. The main portion518is pivotally attached to the bearing bolt542. The actuation member514has a flange portion520extending outwardly from the main portion518to engage the release mechanism476.

In operation of the seat track system410, the seat track system410is in an engaged position. As illustrated, two of the locking pins488engage two of the apertures450in the locking member444. In this position, the locking mechanism486provides positive or continuous engagement of the upper track member428to the lower track member414and the upper track member428is secured to the lower track member414.

To move the seat longitudinally, the release mechanism476is operated by an operator grasping the handle480and rotating the actuation lever478via the cross tube484. When this occurs, the actuation member514is rotated such that the fingers516between the locking pins488engage the flanges492of the locking pins488to move them upwardly against the springs512to exit the apertures450in the locking member444. The upper track member428may then be moved longitudinally relative to the lower track member414.

Once the seat is moved to a new position, the release mechanism476is released by the operator. On the return motion of the actuation lever478being released, this return motion causes the actuation member514to rotate due to the wire spring522such that the fingers516between the locking pins488disengage the flanges492of the locking pins488and the springs512move the locking pins488downwardly. When this occurs, one locking pin488will fall into one of the apertures450of the lower track member414and the second locking pin488engages the locking member444to secure the upper track member428to the lower track member414.

Referring toFIGS. 20 through 24, still another embodiment610, according to the present invention, of the seat track system10is shown. Like parts of the seat track system10have, like reference numerals increased by six hundred (600). In this embodiment, the seat track system610includes the lower track member614, upper track member628, and locking member644. The seat track system610may also include front hook attachment652, distance plate654, rivet656, and locating pin658. The seat track system610includes the forward linkage bracket660, rearward linkage bracket662, reinforcement bracket664, belt buckle bracket666, and rivets668. The seat track system610includes the cross tube attachment bracket670, bearing bushing674, and release mechanism676. The release mechanism676includes the actuation lever678, handle680, end cap682, and cross tube684.

The seat track system610also includes a positive engagement locking mechanism, generally indicated at686, to lock the upper track member628to the locking member644. The locking mechanism686includes a plurality of locking elements such as locking pins688extending vertically and through the apertures650of the locking member644. In the embodiment illustrated, four (4) locking pins688are used to engage two apertures650in the locking member644. Each locking pin688is generally cylindrical in shape and has a frustoconical lower end690to engage the apertures650in the locking member644. Each locking pin688also has a flange692extending radially outwardly a distance spaced from the lower end690to act as a spring seat for a spring to be described. Each locking pin688is made of a metal material such as steel. Two of the locking pins688engage the base portion646through the apertures650of the locking member644for a function to be described. It should be appreciated that a positive locking system provides positive or continuous engagement in any position of the upper track member628to the lower track member614, wherein for any position of the seat, the upper track member628is secured to the lower track member614. It should also be appreciated that in every position of the upper track member628, one locking pin688of the locking system686will always fall into one of the apertures650of the lower track member614. It should further be appreciated that the upper track member628can only move relative to the lower track member614until the locking pin688hits the edge of the aperture650, at that point, the second locking pin688engages the locking member644and eliminates the free-play.

The locking mechanism686also includes a locking pin guide arm694to guide the locking pins688into engagement with the locking member644. The locking pin guide arm694extends longitudinally and is generally rectangular in shape. The locking pin guide arm694extends longitudinally and has a base portion696and a pair of side portions698extending longitudinally from the sides of the base portion696. The locking pin guide arm694has a plurality of guide apertures700extending therethrough and spaced longitudinally for the locking pins688. As illustrated, the locking pin guide arm694has three guide apertures700, one guide aperture700for each locking pin688. The guide bracket694is made of a metal material such as steel. The locking pin guide arm694is disposed within the upper track member628and secured to the upper track member628by a suitable mechanism such as rivets extending through apertures in the side portions698.

The locking mechanism686includes a spring housing701disposed on the base portion630of the upper track member628. The spring housing701extends longitudinally and is generally rectangular in shape. The spring housing701has a plurality of spring cavities703. As illustrated, the spring housing701has three spring cavities703, one spring cavity703for each locking pin688. The spring housing701is made of a metal material such as steel.

The locking mechanism686includes a cover plate704disposed over the spring housing701. The cover plate704extends longitudinally and is generally rectangular in shape. The cover plate704has a main portion705and a pair of side portions706extending downwardly from the sides of the main portion705. The cover plate704is attached to the spring housing701by a suitable mechanism.

The locking mechanism686also includes a plurality of pressure springs712for the locking pins688. One pressure spring712is disposed over one locking pin688and has one end that engages the flange692of the locking pin688and another end that engages the spring housing701. The pressure springs712are compression springs.

The locking mechanism686includes a bearing pin housing730disposed over the cover plate704and mounted to the upper track member628. The bearing pin housing730extends longitudinally and is generally rectangular in shape. The bearing pin housing730has an upper base portion732and a pair of side portions734extending downwardly from the sides of the base portion732. The bearing pin housing730has a flange portion736extending longitudinally from each side portion734. The flange portion736has an aperture738extending therethrough. It should be appreciated that the rivets710previously described extend through the apertures in the flange portions to secure the bearing pin housing730to the upper track member628.

The locking mechanism686includes a distance bushing740secured to each of the side portions734. The locking mechanism686includes a bearing bolt742extending through the distance bushings740. The locking mechanism686includes a compression spring722having a configuration such that one end engages the bearing pin housing730and the other end engages an actuation member714to be described. It should be appreciated that the bearing bolt742is rotatable in the distance bushings740.

The locking mechanism686includes an actuation member714such as an unlocking damper to move the locking pins688. The actuation member714includes a plurality of fingers716extending outwardly. The fingers716are disposed between the locking pins688and engage the flanges692of the locking pins688to move them upwardly against the springs712. The actuation member714has a main portion718extending upwardly from the fingers716. The main portion718is pivotally attached to the bearing bolt742. The actuation member has a flange portion720extending outwardly from the main portion718to engage the release mechanism676.

In operation of the seat track system610, the seat track system610is in an engaged position. As illustrated, two of the locking pins688engage two of the apertures650in the locking member644. In this position, the locking mechanism686provides positive or continuous engagement of the upper track member628to the lower track member614and the upper track member628is secured to the lower track member614.

To move the seat longitudinally, the release mechanism676is operated by an operator grasping the handle680and rotating the actuation lever678via the cross tube684. When this occurs, the actuation member714is rotated such that the fingers716between the locking pins688engage the flanges692of the locking pins688to move them upwardly against the springs612to exit the apertures650in the locking member644. The upper track member628may then be moved longitudinally relative to the lower track member614.

Once the seat is moved to a new position, the release mechanism676is released by the operator. On the return motion of the actuation lever678being released, this return motion causes the actuation member714to rotate due to the compression spring722such that the fingers716between the locking pins688disengage the flanges692of the locking pins688and the springs712move the locking pins688downwardly. When this occurs, one locking pin688will fall into one of the apertures650of the lower track member614and the second locking pin688engages the locking member644to secure the upper track member628to the lower track member614.

According to the present invention, another objective is to provide a locking mechanism for a seat track system which can lock up at any arbitrary seat slide position, the play between the locking pins and the lock apertures provided in the locking member being minimal. Such objects are accomplished by providing a locking mechanism for a seat track system having first and second track members which are parallel to each other and mutually slidable, including: a plurality of locking apertures provided in the locking member rigid connected with the first track member, and fixed on the vehicle floor, holes width being Ln and bridges between the holes being Bn, and n (n=2, 3, 4, . . . ) numbers of moveable locking elements (e.g., pins) connected to the second track member arranged at the pitch Bn+Dn on its longitudinal direction; and at least one locking element is provided on the same phase position of the corresponding locking member so to be engageable and releaseable relative to the locking apertures; wherein Bn=(n−1)*Ln−n*Dn, where Dn is the contact diameter belonging to the locking mechanism having n locking elements (pins). Due to the appropriate pitch of the locking apertures and the appropriate diameter of the locking pins at least one of the locking pins can be engaged by the locking apertures of the locking member at any arbitrary seat slide position.

FIGS. 25athrough25care illustrative views showing the positional relationships between the locking elements such as locking pins888and the locking apertures850when the number of locking elements is n=2. This relationship can apply on both configurations discussed above: lateral or top attachment of locking elements. The locking apertures850on the locking member844are arranged at the equal pitch (B2+L2) along the longitudinal axial line thereof, where B2is the width bridge between two consecutive locking apertures and L2is the locking member slot width. Meanwhile, the moveable locking elements or pins888are provided with a locking pin888at a predefined contact diameter D2. The pitch of the locking pins888is defined as D2+B2. As a result:
D2+B2=L2−D2  (1)
or,
B2=L2−2*D2  (2)

Using this embodiment, adjusting pitch of the track members relative to one another is defined as:
L2−D23)

As illustrated inFIGS. 25ato25c, after adjusting the seat with one step, a similar relative position of the locking pins888relative to the locking apertures850from the locking member844is achieved. With two locking pins888engaged, as shown inFIGS. 25ato25c, two distinct relative engagement positions are possible, after which the engagement cycle is repeated: locking apertures850bridge in between the two locking pins888, and both locking pins888in one locking member844. Depending on the vehicle impact direction (front or rear), at first only one locking pin888will carry the load, the second locking pin888is only provided to eliminate the play. After the first load-carry locking pin888starts bending, the second locking pin888will carry the load also.

FIGS. 26ato26dillustrate a second embodiment in which three locking elements such as locking pins888are engaged in locking apertures850of the locking member844. The pitch of the locking apertures850provided on the locking member844is defined as L3+B3since the pitch of moveable locking pins888is defined as B3+D3. As a result:
2*(L3−D3)+B3+D3=2*(B3+D3)  (4)
or,
B3=2*L3−3*D3  (5)

For this embodiment, three distinct relative engagement positions are possible, after which the engagement cycle is repeated. For this embodiment, the pitch adjustment value is defined as L3−D3and will be smaller than L2−D2if the locking contact diameter D3has the same size order as D2.

FIGS. 27ato27eillustrate a third embodiment in which four locking elements such as locking pins888are engaged in apertures850of the locking member844. The pitch of the locking apertures850provided on the locking member844is defined as L4+B4since the pitch of moveable locking pins888is defined as B4+D4. As a result:
B4=3*L4−4*D4  (6)

To the end of expanding the above described concept to a more general case, it is assumed that there are n moveable locking elements such as locking pins888at the same pitch distance (Bn+Dn) from each other, as illustrated in an embodiment shown inFIGS. 28ato28c. It is also assumed that the pitch of the locking apertures850in the locking member844is Bn+Ln and the width of each locking aperture850is Ln.

In this case, assuming that:
Bn=(n−1)*Ln−n*Dn(7)
then this relation can be put also as:
Ln=Dn+(Bn+Dn)/(n−1)  (8)

The condition under which the bridge between two neighboring locking apertures850can be received by the gap between two neighboring locking pins888can be confirmed as follows:
Bn+Dn=(n−1)*(Ln+Bn)/n(9)
Bn=Bn+Dn−Dn=(n−1)*(Ln+Bn)/n−Dn==[(n−1)*Ln(n−1)*Bn−n*Dn]/n=Bn(10)

The condition under which the external dimension of n locking pins888(n−1)*(Bn+Dn)+Dn can be accommodated within the width (n−2)*(Ln+Bn)+Ln, between the external edges of the locking slots apertures850, can be also examined and confirmed:
(n−2)*(Ln+Bn)+Ln=(n−1)*(Ln+Bn)−(Ln+Bn)+Ln==(n−1)*(Ln+Bn)−Bn=n*(Bn+Dn)−Bn=(n−1)*(Bn+Dn)+Bn+Dn−Bn=(n−1)*(Bn+Dn)+Dn(11)
or,
(n−2)*(Ln+Bn)+Ln=(n−1)*(Bn+Dn)+Dn(12)

The above deductions serve also as inputs in an algorithm to determine automatically the necessary kinematical parameters for simulation of pins position for every longitudinal adjustment position of the track members as function of the tracks pitch.

Although the present invention is described in terms of specific embodiments this is not limited thereby. For instance, the present invention includes the cases in which the dimensional relationships between locking apertures provided in the locking member and moveable locking elements such as locking pins are reversed in relation with the above described embodiments.

For practical reasons, the locking mechanisms with three or four locking pins are the most used.FIGS. 29a-cillustrate the typical variation of pin load force during the travel adjustment in a case of a frontal impact. The free play carrying pin will take the load also when the load carrying locking pin is bent. As illustrated inFIGS. 30a-c, in the case of a locking mechanism with three locking pins, additional load can be carried out by the locking mechanism due to free play carrying locking pin and dropping locking pin engagement during longitudinal adjustment of the track members.

Referring toFIG. 31, a method, according to the present invention and generally shown at900, for automatic determination of position of each locking pin relative to the locking member slot (engaged/disengaged), for a general locking system having n locking pins is illustrated. The method allows for an enhanced computational efficiency in determining the locking pins position relative to the locking member for every longitudinal adjustment, as a function of track integer pitch.

The method900starts at901and advances to an interface module902that allows introduction of a set of specific parameters for a particular type of low seat track system. The method900then advances to module903that allows definition of a particular longitudinal seat track travel adjustment as a function of integer pitch of the seat track, with the bridge between the locking plate slots defined as Bn=(n−1)*Ln−n*Dn. For a particular low seat track system adopted, the method900advances to module904that allows definition of all possible positions, of those n pins relative to locking plate hole slots, as particular two rows and n columns matrices M1, . . . , Mn. The method900then advances to the next module905that allows for verifying the exact nature of a particular adjustment, as an integer of seat track system travel pitch. Finally, the method900advances to module906that determines the unique sought arrangement locking pins-locking slots, as a matrix-element of one row of matrices Bji. The method900then ends at907. It should be appreciated that, for a certain particular travel adjustment, the method provides a very fast and intuitive visual output, required in various kinematical simulations performed during the design of specific low profile seat track system.