Seat slide apparatus for vehicle

A seat slide apparatus for a vehicle includes first and second lower rails, first and second upper rails, first and second lock levers, first and second biasing members, first and second support brackets fixed to the first and second upper rails and including first and second support portions, an operation handle including first and second power transmission portions pressing the first and second lock levers so as to release the restriction of the movement of the upper rails relative to the lower rails against a biasing force of the biasing members, and a release lever rotatably connected to the first upper rail and rotating in association with a forward folding of a seat back of the seat to release the restriction of the movement of the upper rails relative to the lower rails by directly pressing the first power transmission portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 to Japanese Patent Application 2010-174598, filed on Aug. 3, 2010, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a seat slide apparatus for a vehicle.

BACKGROUND DISCUSSION

A known seat slide apparatus for a vehicle is disclosed in JPH11-321393A (which will be hereinafter referred to as Reference 1). The seat slide apparatus disclosed in Reference 1 includes a pair of slide rails parallel to each other in a width direction of a seat for the vehicle and a pair of stoppers provided at the pair of slide rails. Each of the slide rails includes an upper rail and a lower rail. Each of the stoppers is generally in a locked state so as to prevent a movement of the upper rail relative to the lower rail. The locked state of the stopper is released at the same time as when a control bar substantially having a U-shape is pulled upwardly so that an operation force thereof is transmitted to the stopper. Accordingly, a position of the seat is adjustable relative to a floor of the vehicle (i.e., a vehicle floor). The control bar is connected via both end portions thereof to the respective stoppers.

In addition, according to the aforementioned seat slide apparatus disclosed in Reference 1, a slider provided at one of the slide rails (i.e., a first slide rail) moves rearward by an exterior cable that is pulled in association with a forward folding of a seatback of the seat. As a result, the locked state of the stopper provided at the first slide rail is released. Further, a link rotating in association with the rearward movement of the slider is supported at the first slide rail. One end of a connection bar that extends in the width direction of the seat is integrally fixed to the link. The other end of the connection bar is integrally fixed to a lever rotatably supported by the other of the slide rails (i.e., a second slide rail). Because of the rotation of the connection bar via the link in association with the rearward movement of the slider, the lever releases the locked state of the stopper provided at the second slide rail. Accordingly, the locked states of both the stoppers provided at the first and second slide rails respectively are released at the same time in association with the forward folding of the seatback of the seat, thereby achieving the movement of the seat to a foremost position relative to the vehicle floor.

According to the seat slide apparatus disclosed in Reference 1, the connection bar and a surrounding structure thereof may be necessary so as to move both the stoppers at the same time in association with the forward folding of the seat back, which may lead to an increase of the number of components.

A need thus exists for a seat slide apparatus for a vehicle which is not susceptible to the drawback mentioned above.

SUMMARY

According to an aspect of this disclosure, a seat slide apparatus for a vehicle includes first and second lower rails arranged at both sides in a width direction of a seat and extending in a longitudinal direction of the seat, first and second upper rails fixed to the seat and movably connected to the first and second lower rails respectively in the longitudinal direction, first and second lock levers rotatably connected to the first and second upper rails respectively, the first and second lock levers engaging with the first and second lower rails respectively to selectively restrict a movement of the first and second upper rails relative to the first and second lower rails, first and second biasing members biasing the first and second lock levers respectively in such a manner that the movement of the first and second upper rails relative to the first and second lower rails is restricted, first and second support brackets fixed to the first and second upper rails and including first and second support portions respectively, an operation handle integrally including an operating portion that extends in the width direction and first and second power transmission portions extending in the longitudinal direction from both ends of the operating portion to be supported by the first and second support portions, the first and second power transmission portions pressing the first and second lock levers respectively in association with rotations of the first and second power transmission portions relative to the first and second support portions so as to release the restriction of the movement of the first and second upper rails relative to the first and second lower rails by the first and second lock levers against a biasing force of the first and second biasing members, and a release lever rotatably connected to the first upper rail and rotating in association with a forward folding of a seat back of the seat so as to release the restriction of the movement of the first and second upper rails relative to the first and second lower rails by the first and second lock levers by directly pressing the first power transmission portion.

DETAILED DESCRIPTION

An embodiment will be explained with reference to the attached drawings.FIG. 4schematically illustrates a seat apparatus for a vehicle (hereinafter simply referred to as a seat apparatus)1provided at a front-seat side of the vehicle such as an automobile. In the embodiment, directions and orientations such as left, right, front, rear, top, and bottom correspond to those when viewed from a passenger seated on the seat apparatus1. As illustrated inFIG. 4, a lower rail3that extends in a longitudinal direction of the vehicle is fixed to a floor of the vehicle (hereinafter referred to as a floor)2via a pair of leg brackets9. In addition, an upper rail4is mounted on the lower rail3so as to be movable relative thereto.

According to the present embodiment, the lower rail3and the upper rail4serving as a first lower rail and a first upper rail are provided at a first side (for example, a left side) of the seat apparatus1in a width direction of the vehicle while another lower rail3and another upper rail4serving as a second lower rail and a second upper rail are provided at a second side (for example, a right side) of the seat apparatus1in the width direction. InFIG. 4, only the lower rail3and the upper rail4provided at the first side (i.e., the left side) of the seat apparatus1are illustrated. A seat5forming a seating portion for an occupant is fixed to and supported by the two upper rails4. The seat5includes a seat cushion7forming a seating portion and a seat back8supported by a rear edge portion of the seat cushion7so as to be rotatable or tiltable about a rotational axis O. A relative movement between each of the lower rails3and each of the upper rails4is basically restricted. Thus, an operation handle50is provided to release the restricted state of the movement between the lower rail3and the upper rail4.

Next, a seat slide apparatus according to the present embodiment will be explained with reference toFIGS. 1 to 3.FIG. 1is a perspective view illustrating the seat slide apparatus of the present embodiment.FIG. 2Ais a side view of the lower rail3, the upper rail4, and a peripheral structure provided at one side (specifically, at the first side) of the seat slide apparatus when viewed from an exterior side in the width direction.FIG. 2Bis a side view of the lower rail3, the upper rail4, and the peripheral structure provided at the first side of the seat slide apparatus when viewed from an interior side in the width direction.FIG. 3is a cross-sectional view taken along the line III-III illustrated inFIG. 2B.

As illustrated inFIG. 3, each of the lower rails3includes a pair of side wall portions11separating from one another in the width direction and extending in a vertical direction, and a bottom wall portion12connecting lower end portions (i.e., base portions) of the side wall portions11. Folding wall portions13are continuously formed at upper end portions (i.e., end portions) of the side wall portions11respectively so as to extend inwardly in the width direction of the lower rail3and then to fold downwardly towards the base portions of the side wall portions11.

Each of the upper rails4includes a pair of side wall portions14extending in the vertical direction between the folding wall portions13of the lower rail3, and a cover wall portion15connecting upper end portions (i.e., base portions) of the side wall portions14. Folding wall portions16are continuously formed at lower end portions (i.e., end portions) of the side wall portions14so as to extend outwardly in the width direction of the upper rail4and then folding upwardly in such a manner that each of the folding wall portions16is positioned between the side wall portion11and the folding wall portion13.

Each of the lower rails3and each of the upper rails4form an inner void S therebetween in cross sections. Multiple lock bores13aare formed at one of the folding wall portions13inwardly positioned in the width direction of the seat5(i.e., a left side inFIG. 3) (which will be hereinafter referred to as the inward folding wall portion13) over a substantially entire length of the folding wall portion13. The lock bores13aare formed side by side at predetermined intervals in the longitudinal direction of the inward folding wall portion13. A through-hole4ais formed at a substantially center portion of each of the upper rails4in the longitudinal direction. The through-hole4ais formed by a cutting of a corner portion defined by the cover wall portion15and the side wall portion14positioned inwardly in the width direction of the seat5(which will be hereinafter referred to as the inward side wall portion14). Multiple insertion bores14aare formed side by side at the predetermined intervals at a lower portion of the inward side wall portion14. Specifically, the insertion bores14aare provided within a range where the through-hole4ais formed in the longitudinal direction. Multiple insertion holes16a, of which the number is the same as the number of insertion bores14a, are formed side by side at the predetermined intervals at the folding wall portion16that is continuously connected to the inward side wall portion14. The insertion bores14aand the insertion holes16aare arranged so as to face one another in the width direction and are positioned so as to match a portion of the lock bores13aof the lower rail3of which the number is the same as the number of the insertion bores14aor the insertion holes16a.

A lock lever21made of a plate member is rotatably connected via a bracket23to each of the upper rails4within the range of the through-hole4ain the longitudinal direction. The lock lever21includes a body portion21ahaving a flat plate shape and a pair of support pieces21b. The support pieces21bare bent to extend upwardly from respective lower ends of the body portion21ain the longitudinal direction of the upper rail4. The lock lever21is supported via the support pieces21bat an outer side of the inner void S so as to be rotatable about a rotational axis O1that extends in the longitudinal direction of the upper rail4. The lock lever21also includes multiple lock claws21cthat extend towards the inner void S through the through-hole4aand that are bent back to the outside (i.e., the left side inFIG. 3) of the inner void S. The lock claws21care formed at the predetermined intervals in the longitudinal direction while the number of lock claws21cis the same as the number of the insertion bores14aor the insertion holes16a. The lock claws21care arranged in such a manner to be engageable and disengageable relative to the insertion bores14aand the insertion holes16awhile the lock lever21is rotating about the rotational axis O1.

In a case where the lock claws21care inserted into the corresponding lock bores13ain addition to the insertion bores14aand the insertion holes16a, the relative movement between the lower rail3and the upper rail4is restricted. On the other hand, in a case where the lock claws21cdisengage from the corresponding insertion holes16a, the lock bores13a, and the insertion bores14asequentially, the restricted state of the relative movement between the lower rail3and the upper rail4is released (i.e., the relative movement between the lower rail3and the upper rail4is permitted.

Further, the lock lever21includes a contact portion21dthat inclines downwardly from an upper portion of the body portion21a. As illustrated inFIG. 1, a torsion wire22is provided at an upper portion of each of the upper rails4. That is, two of the torsion wires22serving as first and second biasing members are provided at the upper rails4at the first side and the second side respectively. One end of each of the torsion wires22engages with the lock lever21while the other end of the torsion wire22engages with the bracket23. Each of the lock levers21is constantly biased by the torsion wire22so as to rotate in a direction where the lock claws21care inserted into the insertion bores14a, the insertion holes16a, and the lock bores13a(i.e., the lock lever21is biased to rotate in a clockwise direction inFIG. 3).

A support bracket31formed by a plate member is fixed to each of the upper rails4. The support bracket31is arranged at a front side of the lock lever21in the longitudinal direction. The support bracket31includes a fitting wall portion32and a first side wall portion33. The fitting wall portion32extends in the width direction of the upper rail4so as to be tightened to the cover wall portion15thereof. The first side wall portion33extends downwardly from an end of the fitting wall portion32so as to surround the side wall portion11of the lower rail3inwardly positioned in the width direction. The support bracket31also includes a bottom wall portion34, a second side wall portion35, and a support wall portion36. The bottom wall portion34extends inwardly in the width direction of the seat5from a lower end of the first side wall portion33. The second side wall portion35extends upwardly from an end of the bottom wall portion34while having a triangular shape. The support wall portion36extends from a front end of the first side wall portion33inwardly in the width direction of the seat5. A support bore37having a rectangular shape is formed at the support wall portion36so as to open in the longitudinal direction of the upper rail4.

A torsion spring41formed by a single wire rod is attached to each of the support brackets31. One end of the torsion spring41engages with the first side wall portion33while the other end of the torsion spring41engages with the second side wall portion35. An extension portion43is formed between the both ends of the torsion spring41so as to have a U-shape. A downward biasing force is generated at the extension portion43relative to the both ends of the torsion spring41.

An operation handle50is connected to both the support brackets31serving as first and second support brackets. The operation handle50includes a handle body portion51formed by a cylindrical member that is bent. The handle body portion51integrally includes an operating portion51aand end portions51bserving as first and second power transmission portions so as to substantially form into a loop shape. The operating portion51aextends in the width direction of the seat5at a front side of the lower rails3, and the like. The end portions51bare bent from both ends of the operating portion51atowards the respective lock levers21serving as first and second lock levers in the longitudinal direction of the upper rails4. The handle body portion51also includes pressing portions52each serving as an edge portion and each formed by being pressed in the vertical direction into a flat plate shape. The handle body portion51further includes holding grooves53each having a slit shape. Specifically, each of the holding grooves53is formed at a portion in the vicinity of each of the pressing portions52, i.e., at a side facing the operating portion51a. The holding groove53is formed so that an upper portion thereof is cut out in the width direction of the seat5.

The handle body portion51is supported by the support wall portions36in such a manner that the end portions51bare inserted into the support bores37, serving as first and second support portions and first and second support bores, of the support wall portions36respectively in the longitudinal direction of the upper rails4. In addition, the handle body portion51is connected to the lock levers21in such a manner that the pressing portions52are placed on the contact portions21dof the lock levers21respectively as illustrated inFIG. 3. At this time, the extension portions43of the torsion springs41are fitted to the respective holding grooves53so that the end portions51bof the handle body portion51engage with the support brackets31and thus the end portions51bare restrained from disengaging from the support brackets31in a state where upper portions of the end portions51bare biased downwardly at the holding grooves53.

As illustrated inFIG. 2B, a contact portion of each of the support wall portions36(specifically, each of the support bores37) relative to an upper portion of each of the end portions51bof the handle body portion51serves as a rotation reference point at which the handle body portion51rotates. Thus, each of the support wall portions36supports the handle body portion51to be rotatable at a rotational axis O2specified at the contact portion between the support wall portion36and the upper portion of the end portion51b. The rotation reference point of the handle body portion51is defined by the support bracket31(the support wall portion36) because of a usage of principle of leverage, thereby balancing an operation force of the handle body portion51for releasing the locked state of the lock lever21. The rotation direction of the handle body portion51rotating at the rotational axis O2is different from the rotation direction of the lock lever21rotating at the rotational axis O1. The torsion springs41elastically hold the handle body portion51at a predetermined initial position so as to maintain the connected state between the handle body portion51and the lock levers21.

As illustrated inFIG. 1, the operation handle50includes a reinforcement portion56obtained by a cylindrical member that is bent. The reinforcement portion56integrally includes a connecting portion56aand a pair of fixing portions56bserving as first and second fixing portions. The connecting portion56aextends in the width direction of the seat5at a rear side of the operating portion51a. The fixing portions56bare bent from both ends of the connecting portion56atowards the respective lock levers21in the longitudinal direction of the upper rails4. The fixing portions56bof the reinforcement portion56are fixed to respective inner side surfaces of the end portions51bin the width direction of the seat5by welding, or the like. As illustrated inFIG. 2B, in a case where each of the end portions51bof the handle body portion51is rotatably supported by each of the support bores37, an end surface of the fixing portion56bis in contact with a front end portion of the support bore37(i.e., an end portion facing the operating portion51ain the longitudinal direction of the seat5). Each of the fixing portions56bis fixed to each of the end portions51bat a contact position relative to the front end portion of each of the support bores37. The aforementioned contact position is the closest to a position where each of the pressing portions52of the end portion51bpresses the upper surface of each of the lock levers21within a range close to the operating portion51arelative to the support bore37in the longitudinal direction of the seat5where an arrangement restriction may not be generally affected.

As illustrated inFIG. 1, a supporting bracket29is tightened to an upper surface of the cover wall portion15of each of the upper rails4. That is, two of the supporting brackets29serving as first and second supporting brackets are provided at the upper rails4at the first side and the second side respectively. The supporting bracket29is formed by a plate member that is bent in an L-shape so as to extend upwardly at the inner side in the width direction of the seat5. A bottom wall portion of the supporting bracket29has a concave-convex surface so as to avoid an interference with the lock lever21and the support bracket31. An auxiliary bracket71having a plate shape is tightened to a substantially intermediate portion of one of the supporting brackets29(i.e., the supporting bracket29shown in a lower right side inFIG. 1, i.e., the supporting bracket29at the first side). As illustrated inFIG. 2B, the auxiliary bracket71includes a cable support portion71ahaving a flange shape and a spring support portion71bhaving a flange shape. The cable support portion71aextends inwardly in the width direction of the seat5from a rear edge of the auxiliary bracket71. The spring support portion71bextends inwardly in the width direction of the seat5from a front edge of the auxiliary bracket71.

A support pin72penetrates in the width direction of the seat5through the supporting bracket29and an intermediate portion of the auxiliary bracket71in the longitudinal direction of the seat5between the support wall portion36and the pressing portion52. The support pin72is provided at an upper side of the pressing portion52. Then, a release lever73, a power transmission lever74, and a memory lever80, each having a plate shape, are rotatably supported by the support pin72. The release lever73is provided at the inner side in the width direction of the seat5relative to the auxiliary bracket71, and the like while the power transmission lever74and the memory lever80are provided at the outer side in the width direction of the seat5relative to the auxiliary bracket71, and the like. The release lever73, the power transmission lever74, and the memory lever80possess a common rotational center, i.e., a rotational center O3that extends in the width direction of the seat5. The release lever73, the power transmission lever74, the memory lever80, and the auxiliary bracket71are only provided at the upper rail4at the first side according to the present embodiment.

The release lever73includes a first extending portion73aand a pressing piece73bhaving a flange shape. The first extending portion73aextends radially relative to the rotational center O3to a rear side thereof. The pressing piece73bextends inwardly in the width direction of the seat5from a lower rear edge of the first extending portion73a. The pressing piece73bis arranged above the pressing portion52while being positioned on a rotation locus relative to the rotational center O3. Accordingly, in a case where the release lever73rotates in a counterclockwise direction inFIG. 2Babout the support pin72, the pressing piece73bdirectly presses the upper surface of the pressing portion52. The rotational center O3of the release lever73is positioned at an intermediate portion in the longitudinal direction of the seat5between the support bore37and a position where the pressing piece73bof the release lever73presses the upper surface of the pressing portion52. As a result, when the release lever73rotates while pressing the pressing portion52, the position where the pressing piece73bof the release lever73presses the upper surface of the pressing portion52is displaced towards the support bore37.

The release lever73also includes a second extending portion73cand an engagement bore73d. The second extending portion73cextends radially relative to the rotational center O3to a front upper side thereof. The engagement bore73dis formed at a front end of the second extending portion73c. An end portion of an inner wire75bpulled from an external cable portion75aof a release cable75that is held by the cable support portion71aengages with the engagement bore73d. The release cable75is connected to the seat back8and is configured in such a manner that the inner wire75bis pulled within the external cable portion75ain association with the forward folding of the seat back8. At this time, the release lever73rotates about the support pin72in a counterclockwise direction inFIG. 2B. A power transmission pin76is fixed to the second extending portion73cso as to extend externally in the width direction of the seat5. Specifically, the power transmission pin76is arranged at an intermediate portion in the longitudinal direction of the seat5between the rotational center O3and the engagement bore73dof the release lever73.

The power transmission lever74includes a spring support piece74aand an engagement piece74bto thereby substantially form into a V-shape. The spring support piece74aand the engagement piece74bradially extend relative to the rotational center O3to an upper side and an upper rear side respectively. The power transmission pin76is inserted into a portion between the spring support piece74aand the engagement piece74b. Therefore, in a case where the release lever73rotates about the support pin72in the clockwise direction inFIG. 2A, the engagement piece74bof the power transmission lever74is pressed by the power transmission pin76so that the release lever73and the power transmission lever74integrally rotate. On the other hand, in a case where the power transmission lever74rotates about the support pin72in the counterclockwise direction inFIG. 2A, the power transmission pin76is pressed by the engagement piece74bso that the power transmission lever74and the release lever73integrally rotate.

A return spring77is disposed between the auxiliary bracket71and the power transmission lever74. Specifically, one end of the return spring77engages with the spring support portion71bof the auxiliary bracket71while the other end of the return spring77engages with the spring support piece74aof the power transmission lever74. The return spring77generates a biasing force in a direction where the release lever73rotates in the clockwise direction inFIG. 2Bvia the power transmission lever74and the power transmission pin76, i.e., in a direction where the inner wire75bis pulled out from the external cable portion75a. Accordingly, the release lever73returns to a position upwardly away from the pressing portion52in a state where the release lever73is released from an operational force of the release cable75(i.e., in a state where the seat back8returns from the forward folding state).

The memory lever80includes a spring support piece80aand a memory engagement piece80bto be formed into an L-shape. The spring support piece80aand the memory engagement piece80bextend radially relative to the rotational center O3to a front side and a lower side respectively. A holding spring81is disposed between the memory lever80and the power transmission lever74. Specifically, one end of the holding spring81engages with the spring support piece74aof the power transmission lever74while the other end of the holding spring81engages with the spring support piece80aof the memory lever80. The holding spring81includes an elastic coefficient sufficiently larger than that of the return spring77. That is, the memory lever80is connected to the power transmission lever74via the holding spring81so as to substantially integrally rotate with the power transmission lever74.

The memory lever80is contactable with a memory pin via the memory engagement piece80bthat extends towards the inner void S through the upper rail4(specifically, the cover wall portion15thereof). The memory pin is provided so as to store a position of the seat5(i.e., the memory pin performs a storage operation) immediately before the seat5moves in association with the forward folding of the seat back8of the seat5. The memory lever80integrally rotates with the release lever73and the like in the aforementioned manner in association with the forward folding of the seat back8to thereby engage with the memory pin that then performs the storage operation.

An operation of the seat slide apparatus according to the present embodiment will be explained below. First, the operation handle50is operated so that the operating portion51ais pulled up. Then, both the end portions51bof the handle body portion51of the operation handle50rotate at the rotational axis O2in a direction that corresponds to the counterclockwise direction inFIG. 2B. At this time, both the pressing portions52of the handle body portion51move downwardly, thereby pressing down the respective upper surfaces of the contact portions21dof the lock levers21. Then, the lock levers21rotate at the rotational axis O1against a biasing force of the torsion wires22in a direction where the lock claws21cdisengage from the insertion bores14a, and the like as illustrated inFIG. 3. Accordingly, the restriction of the relative movement between the lower rail3and the upper rail4at the first side and the restriction of the relative movement between the lower rail3and the upper rail4at the second side are released at the same time.

Afterwards, when the operation handle50is released (i.e., an operation force of the operating portion51ais cancelled), the lock levers21rotate at the rotational axis O1in a direction where the lock claws21cengage with the insertion bores14a, and the like as illustrated inFIG. 3. Accordingly, the relative movement between the lower rail3and the upper rail4at the first side and the relative movement between the lower rail3and the upper rail4at the second side are restricted at the same time. At this time, the end portions51bof the operation handle50rotate at the operational axis O2in a direction that corresponds to the clockwise direction inFIG. 2Bin association with the rotations of both the lock levers21.

Accordingly, because of the operation of the operation handle50and the release thereof afterwards, the position of the seat5is desirably adjusted relative to the floor2in the longitudinal direction of the seat5. A seat slide mechanism is therefore achieved according to the present embodiment. On the other hand, in a case where the inner wire75bis pulled within the external cable portion75aof the release cable75in association with the forward folding of the seat back8, the release lever73together with the power transmission lever74and the memory lever80rotate in the counterclockwise direction inFIG. 2Bat the rotational center O3against the biasing force of the return spring77. At this time, the release lever73(specifically, the pressing piece73b) directly presses the upper surface of one of the pressing portions52of the operation handle50. Thus, one of the pressing portions52(i.e., the pressing portion52at the first side) that is pressed by the release lever73moves downward in a state where the end portion51brotates about the rotational axis O2in the counterclockwise direction inFIG. 2B. The pressing portion52presses the upper surface of the contact portion21dof the lock lever21at the first side.

The rotation of one of the end portions51b(i.e., the end portion51bat the first side) is transmitted via the operating portion51ato the other of the end portions51b(i.e., the end portion51bat the second side). At this time, because the rigidity of the operation handle50is enhanced by the reinforcement portion56, the operation handle50when rotating in association with the release lever73, and the like is restrained from being deformed. Accordingly, the pressing portion52at the second side also moves downward to press the upper surface of the contact portion21dof the lock lever21at the second side downwardly.

Accordingly, in association with the forward folding of the seat back8, both the lock levers21rotate in the direction where the lock claws21cdisengage from the insertion bores14a, and the like as illustrated inFIG. 3. Then, the restriction of the relative movement between the lower rail3and the upper rail4at the first side and the restriction of the relative movement between the lower rail3and the upper rail4at the second side are released. In a state where the seat back8is folded and positioned forward, the restriction of the relative movement between the lower rail3and the upper rail4at the first side and the restriction of the relative movement between the lower rail3and the upper rail4at the second side are released. Therefore, because of the forward folding of the seat back8, the seat5may move to a foremost position relative to the floor2(which is a so-called walk-in mechanism).

In association with the forward folding of the seat back8, the memory lever80rotates together with the release lever73and the like so that the memory pin that engages with the memory lever80performs the memory operation. Accordingly, in a case where the seat5that is moved to the foremost position relative to the floor2is then moved rearward while the seat5is being folded forward, the seat5returns to the position immediately before the forward folding of the seat back8that is stored during the memory operation by the memory pin.

According to the aforementioned embodiment, at a time of the forward folding of the seat back8, the release lever73provided at the upper rail4at the first side directly presses the upper surface of the pressing portion52of the end portion51bat the first side. Then, the end portion51bat the second side also rotates to thereby release the restriction of the relative movement between the lower rails3and the upper rails4at the first and second sides by the respective lock levers21. Therefore, the number of components for the seat slide apparatus may be reduced compared to a case where a connecting bar is provided so as to bring the lock levers21at the first and second sides to operate together or a case where the release levers are provided at both the upper rails4.

According to a seat slide apparatus for a vehicle disclosed in JPH11-321393A, a control bar corresponding to the operation handle50and stoppers corresponding to the lock levers21of the present embodiment are connected to one another. Thus, the control bar and the stoppers apparently operate in association with one another. However, because a connection bar is provided to bring both the stoppers to operate together, it may be obvious that even when one of the stoppers operates, the other of the stoppers does not operate via the control bar.

According to the present embodiment, the rotational center O3of the release lever73extends in the width direction of the seat5at an upper side of the end portion51b. The rotational center O3is arranged at the intermediate portion in the longitudinal direction of the seat5between the support bore37and the position where the release lever73presses the upper surface of the pressing portion52. Therefore, in a case where the release lever73rotates in association with the forward folding of the seat back8, the end portion51bat the first side of which the upper surface is directly pressed by the release lever73rotates in such a manner to be pressed down relative to the support bore37provided at the upper rail4at the first side. At this time, when the release lever73rotates while pressing the pressing portion52, the position where the pressing piece73bof the release lever73presses the upper surface of the pressing portion52is displaced towards the support bore37. Thus, even when the rotation amount of the release lever73increases until the restriction of the relative movement between the lower rail3and the upper rail4by the lock lever21is released, the release lever73stably presses the upper surface of the pressing portion52.

In addition, according to the present embodiment, the operation handle50securely transmits the rotation of the end portion51bat the first side to the end portion51bat the second side by a rigidity increase of the reinforcement portion56. Further, in a case where the end portions51bare inserted into the respective support bores37, the operation handle50is appropriately positioned because the fixing portions56bof the reinforcement portion56make contact with the front end portions of the support bores37of the support wall portions36respectively. As a result, each of the end portions51bis restrained from being excessively inserted into the support bore37. Furthermore, each of the fixing portions56bis fixed to each of the end portions51bat a contact position with the front end portion of each of the support bores37. The aforementioned contact position is the closest to a position where each of the pressing portions52of the end portion51bpresses the upper surface of each of the lock levers21within a range close to the operating portion51arelative to the support bore37in the longitudinal direction of the seat5where an arrangement restriction may not be generally affected. Therefore, a deformation of the operation handle50that may be generated when the rotation of the end portion51bat the first side is transmitted to the end portion51bat the second side may be effectively restrained.

Further, according to the present embodiment, each of the pressing portions52is formed into a flat plate. Thus, the pressing piece73bof the release lever73makes a line contact with the upper surface of the pressing portion52. Thus, the release lever73stably presses the upper surface of the pressing portion52.

Furthermore, according to the present embodiment, the pressing portions52of the operation handle50are prevented from being connected to the respective lock levers21. Then, the upper surfaces of the lock levers21are pressed by the pressing portions52respectively. The occupant of the seat5generally fastens a seatbelt. Thus, in the event of a vehicle collision, a remarkably large moment is applied to the seat5via a buckle of the seatbelt fixed to the seat5. In this case, positions or shapes of the lower rails3at the first side and the second side are unbalanced, which may cause an interference of one of the end portions51bof the operation handle50with the floor2. Then, the pressing portion52of one of the end portions51bmay rotate and press the upper surface of the lock lever21. However, because the pressing portions52of the operation handle50are not connected to the respective lock levers21, the possible rotation of the pressing portion52of one of the end portions51bis absorbed by a movable range of the pressing portion52of the other of the end portions51brelative to the upper surface of the lock lever21.

The present embodiment may be modified as follows. The rotational center O3of the release lever73may be arranged in a direction away from the support bore37relative to the position where the release lever73presses the upper surface of the pressing portion52in the longitudinal direction of the seat5. In this case, when the release lever73rotates in association with the forward folding of the seat5, one of the end portions51bof which the upper surface of the pressing portion52is directly pressed by the release lever73(i.e., the end portion51bat the first side) rotates so as to be pressed downward relative to the support bore37. At this time, the position where the release lever73presses the upper surface of the pressing portion52is away from the support bore37in association with the increase of the rotation amount of the release lever73. That is, a force required to press down the end portion51brelative to the support bore37decreases in association with the increase of the rotation amount of the release lever73. On the other hand, the biasing force of each of the torsion wires22increases in association with the release of the restriction of the relative movement between the lower rail3and the upper rail4by the lock lever21, i.e., in association with the increase of the rotation amount of the release lever73. Accordingly, while the biasing force of the torsion wire22is increasing in association with the increase of the rotation amount of the release lever73, the force required to press down the end portion51bof the operation handle50is decreasing. Consequently, for example, a fluctuation of load applied to the release lever73may be reduced as a whole.

Further, each of the support brackets31may rotatably support the operation handle50by a pin concentric to the rotational axis O2instead of each of the support bores37.

Furthermore, a portion of the operation handle50by which each of the lock levers21is pressed or a portion of the operation handle50that is pressed by the release lever73may not be limited to the edge portion (i.e., the pressing portion52) of the operation handle50. Any portion between a support portion and an end of the end portion51bmay be applicable.

Furthermore, a portion of each of the lock levers21where the end portion51bof the operation handle50presses down may not be limited to the upper surface. An appropriate portion of the lock lever21that is brought to the unlocked state may be specified depending on the shape of the lock lever21.

Furthermore, configurations or components related to the memory operation storing a position of the seat5in the longitudinal direction thereof at the time of the forward folding of the seat back8, such as the power transmission lever74, the power transmission pin76, the return spring77, the memory lever80, the holding spring81, and the like may be omitted.

Furthermore, the biasing member engaging with the lock lever21may be a plate spring, a coil spring, or the like instead of the torsion wire22. The moving direction of the upper rail4relative to the lower rail3may correspond to the width direction of the vehicle.

According to the embodiment, in a case where an operation force is applied to the operating portion51aof the operation handle50to thereby rotate the end portions51babout the respective support bores37, the end portions51bpress the lock levers21. As a result, the restricted state of the movement of the upper rails4relative to the lower rails3is released against the biasing force of the torsion wires22. Accordingly, the movement of the upper rails4relative to the lower rails3, i.e., the movement of the seat5is permitted. In addition, in a case where the release lever73rotates in association with the forward folding of the seat back8of the seat5, the end portion51bat the first side that is directly pressed by the release lever73rotates about the support bore37. On the other hand, in a case where the end portion51bat the first side rotates, the aforementioned rotation is transmitted to the end portion51bat the second side via the operating portion51aof the operation handle50. Then, the end portion51bat the second side rotates about the support bore37. The end portions51brotate to press the respective lock levers21, and therefore the restriction of the movement of the upper rails4relative to the lower rails3by the lock levers21is released against the biasing force of the torsion wires22. In association with the forward folding of the seat back8, the movement of the upper rails4relative to the lower rails3, i.e., the movement of the seat5is permitted. Accordingly, the release lever73provided at the upper rail4directly presses the end portion51bat the first side, which leads to the rotation of the end portion51bat the second side so as to release the restricted state of the movement between the upper rail4and the lower rail3by the lock lever21at the second side. As a result, the number of components for the seat slide apparatus according to the present embodiment may be reduced as compared to a case where a connecting rod is provided to bring the lock levers21to operate together, a case where both the upper rails4are equipped with the release levers73, and the like.

According to the aforementioned embodiment, the support portions include the support bores37opening in the longitudinal direction. The operation handle50releases the restriction of the movement of the upper rails4relative to the lower rails3by the lock levers21by the pressing portions52of the end portions51bpressing the upper surfaces of the lock levers21in association with the rotations of the end portions51brelative to the support bores37. The end portions51bare inserted into the support bores37respectively. The release lever73rotates in association with the forward folding of the seat back8of the seat5so as to directly press the upper surface of the pressing portion52of the end portion51bat the first side.

Further, according to the aforementioned embodiment, the rotational center O3of the release lever73extends in the width direction of the seat5at the upper side of the end portion51bat the first side. The rotational center O3is arranged at the intermediate position in the longitudinal direction of the seat5between the support bore37and the position where the release lever73presses the end portion51bat the first side.

Accordingly, in a case where the release lever73rotates in association with the forward folding of the seat back8, the end portion51bat the first side directly pressed by the release lever73rotates so as to be pressed down relative to the support bore37. At this time, when the release lever73rotates while pressing the end portion51b, the position where the release lever73presses down the end portion51bis displaced towards the support bore37. Thus, even when the release lever73further rotates until the restriction of the relative movement between the upper rails4and the lower rails3is released, the end portion51bat the first side is stably pressed by the release lever73.

Furthermore, according to the aforementioned embodiment, the rotational center O3of the release lever73extends in the width direction of the seat5at the upper side of the end portion51bat the first side. The rotational center O3is arranged at a side away from the support bore37relative to the position where the release lever73presses the end portion51bat the first side.

Accordingly, in a case where the release lever73rotates in association with the forward folding of the seat back8, the end portion51bat the first side directly pressed by the release lever73rotates so as to be pressed down relative to the support bore37at the first side. At this time, the position where the release lever73presses the end portion51bis away from the support bore37at the first side in association with the increase of the rotation amount of the release lever73. That is, a force required to press down the end portion51b(the operation handle50) relative to the support bore37decreases in association with the increase of the rotation amount of the release lever73. On the other hand, the biasing force of each of the torsion wires22increases in association with the release of the restriction of the relative movement between the lower rail3and the upper rail4by the lock lever21, i.e., in association with the increase of the rotation amount of the release lever73. Accordingly, while the biasing force of the torsion wire22is increasing in association with the increase of the rotation amount of the release lever73, the fore required to press down the end portion51bof the operation handle50is decreasing. Consequently, for example, a fluctuation of load applied to the release lever73may be reduced as a whole.

Furthermore, according to the aforementioned embodiment, the operation handle50includes the reinforcement portion56restraining a deformation of the operation handle50in a case where a rotation of the end portion51bat the first side is transmitted to the end portion51bat the second side.

Accordingly, the operation handle50securely transmits the rotation of the end portion51bat the first side to the end portion51bat the second side by a rigidity increase of the reinforcement portion56.

Furthermore, according to the aforementioned embodiment, the support bores37are arranged at the inner side in the width direction of the seat5relative to the upper rails4respectively, and the reinforcement portion56integrally includes the connecting portion56athat extends in the width direction, and the fixing portions56bthat extend from both ends of the connecting portion56in the longitudinal direction of the seat5to be fixed to the inner side surfaces of the end portions51bin the width direction respectively. The fixing portions56bmake contact with the front end portions of the support bores37facing the operating portion51a.

The operation handle50is positioned by the contact between the fixing portions56bof the reinforcement portion56and the front end portions of the support bores37in a case where the end portions51bare supported by the respective support bores37. Specifically, the end portions51bare restrained from being excessively inserted into the respective support bores37. In addition, even in a case where the occupant of the seat5presses the operation handle50by his/her heel by accident in the event of a vehicle collision, for example, the end portions51bare restrained from being excessively inserted into the support bores37. Further, each of the fixing portions56bis fixed to each of the end portions51bat a contact position with the front end portion of each of the support bores37. The aforementioned contact position is the closest to a position where each of the pressing portions52of the end portion51bpresses the upper surface of each of the lock levers21within a range close to the operating portion51arelative to the support bore37in the longitudinal direction of the seat5where an arrangement restriction may not be affected. Therefore, a deformation of the operation handle50that may be generated when the rotation of the end portion51bat the first side is transmitted to the end portion51bat the second side may be effectively restrained.

Furthermore, according to the aforementioned embodiment, the release lever73includes the first extending portion73aextending radially relative to the rotational center O3to a rear side and the pressing piece73bextending inwardly in the width direction of the seat5from a lower rear edge of the first extending portion73a. The pressing piece73bis arranged at an upper side of the pressing portion52of the end portion51bat the first side while being positioned on a rotation locus relative to the rotational center O3.

Furthermore, according to the aforementioned embodiment, the release lever73includes the second extending portion73cextending radially relative to the rotational center O3to a front upper side and the engagement bore73dformed at a front end of the second extending portion73c, the engagement bore73dwith which the release cable75connected to the seat back8engages.

Furthermore, according to the aforementioned embodiment, the seat slide apparatus further includes the supporting brackets29tightened to the upper surfaces of the upper rails4respectively, each of the supporting brackets29extending upwardly at the inner side in the width direction of the seat5, and the auxiliary bracket71tightened to the intermediate portion of the supporting bracket29at the first side in the longitudinal direction. The auxiliary bracket71includes the cable support portion71aextending inwardly in the width direction of the seat5from a rear edge of the auxiliary bracket71and the spring support portion71bextending inwardly in the width direction of the seat5from a front edge of the auxiliary bracket71. The release cable75includes the external cable portion75aheld by the cable support portion71aand the inner wire75bpulled out from the external cable portion75aand engaging with the engagement bore73dformed at the second extending portion73cof the release lever73. The inner wire75bis pulled within the external cable portion75ain association with the forward folding of the seat back8.

Furthermore, according to the aforementioned embodiment, the fixing portions56bare fixed to the end portions51bat the contact positions relative to the front end portions of the support bores37respectively, each of the contact positions being the closest to the position where each of the pressing portions52of the end portion51bpresses the upper surface of each of the lock levers21within the range close to the operating portion51arelative to the support bore37in the longitudinal direction of the seat5.

Furthermore, according to the aforementioned embodiment, the operation handle50includes the reinforcement portion56restraining a deformation of the operation handle50in a case where a rotation of the end portion51bat the first side is transmitted to the end portion51bat the second side. The support bores37are arranged at an inner side in the width direction of the seat5relative to the upper rails4respectively. The reinforcement portion56integrally includes the connecting portion56athat extends in the width direction, and fixing portions56bthat extend from both ends of the connecting portion56ain the longitudinal direction of the seat5to be fixed to inner side surfaces of the end portions51bin the width direction respectively. The fixing portions56bmake contact with the front end portions of the support bores37facing the operating portion51a.