Abstract:
A sliding-type automobile seat comprising a seat cushion frame, a slide rail mechanism for allowing the seat to be slidingly moved, slide lock mechanisms for causing the seat to be releasably locked at predetermined positions, a substantially U-shaped operating lever for causing the seat to be released from a locked state, and connection mechanisms for causing both end portions of the substantially U-shaped operating lever to the slide lock mechanisms, the slide rail mechanism comprising a pair of parallel lower rails mounted on a floor surface of an automobile, and a pair of parallel upper rails attached to a lower portion of the seat cushion frame and slidably engaged with the pair of parallel lower rails, each of the slide lock mechanisms comprising a lock member swingably mounted to a corresponding upper rail and urged upward at one end portion thereof by a spring, the lock member including a first engaging member, and a second engaging member provided at a corresponding lower rail, the first engaging member and the second engaging member being adapted to be releasably engaged with each other, to thereby cause the seat to be locked at the predetermined positions, each of the connection mechanisms comprising a connection member having a member for stoppingly engaging the lock member, and the member for stoppingly engaging the lock member being engaged with the lock member, whereby the operating lever is connected, via the connection mechanisms, to the slide rock mechanism by one-touch operation.

Description:
TECHNICAL FIELD 
   The present invention relates to a sliding-type automobile seat that can be slidingly moved, via a slide rail mechanism, forward and rearward in an automobile. 
   BACKGROUND ART 
   As a sliding-type automobile seat of this kind, a sliding-type automobile seat is disclosed in Japanese Patent Application Laid-Open No. 2004-51082. Referring now to  FIGS. 1 to 5 , the conventional sliding-type automobile seat will be discussed in order to facilitate understanding of the present invention. As shown in  FIG. 1 , this automobile seat includes a seat cushion frame  1  for a seat cushion thereof. The seat cushion frame  1  comprises a pair of spaced apart side frame sections  1   a , a pan frame section  1   b  arranged and fixed between forward portions of the side frame sections  1   a , and a rear frame section  1   c  arranged and fixed between rearward portions of the side frame sections  1   a.    
   The automobile seat can be slidingly moved forward and rearward in an automobile via a slide rail mechanism  2 . As shown in  FIG. 2 , the slide rail mechanism  2  comprises upper rails  2   a  attached to lower portions of the side frame sections  1   a  (only one side frame section  1   a  and only one upper rail  2   a  are shown in  FIG. 2 ), and a pair of parallel lower rails  2   b  mounted on a floor surface of the automobile via stand leg portions  3   a ,  3   b  (only one lower rail  2   b  is shown in  FIG. 2 ). The upper rails  2   a  are slidably engaged with the lower rails  2   b  as will be fully discussed hereinafter, whereby the seat can be slidingly moved forward and rearward in the automobile. 
   As shown in  FIG. 3 , each of the upper rails  2   a  (only one upper rail  2   a  is shown in  FIG. 3 ) comprises a pair of members  20   a ,  20   b  of substantially J-shapes in vertical-section that are fixed back-to-back to a lower portion of a corresponding side frame section  1   a  of the automobile seat by a support pin  40  and hang downward from the side frame section  1   a . Each of the lower rails  2   b  (only one lower rail  2   b  is shown in  FIG. 3 ) has a longitudinal body  21  of a substantially U-shape in cross-section and is mounted on the floor surface of the automobile with an opening portion thereof facing upward. The lower rail body  21  includes inward bent flanges  22   a ,  22   b  of substantially L-shapes in cross-section that are bent inward from both ends of the substantially U-shaped lower rail body  21  in such a manner to allow a space to be produced between the inward bent flanges  22   a ,  22   b.    
   Each of the upper rail  2   a  is combined with a corresponding lower rail  2   b  by causing lower curved portions  20   a ′,  20   b ′ of the substantially J-shaped members  20   a ,  20   b  hanging downward from the side frame section la to be inserted into the substantially U-shaped lower rail body  21  through the space between the inward bent flanges  22   a ,  22   b  of the lower rail body  21 , and causing tip end portions of the lower curved portions  20   a ′,  20   b ′ to be arranged inside the inward bent flanges  22   a ,  22   b  of the lower rail body  21 . Moreover, between the lower curved portions  20   a ′,  20   b ′ of the substantially J-shaped members  20   a ,  20   b  of the upper rail body  21  and a bottom surface of the lower rail body  21 , a plurality of rollers  23  are disposed (only one roller  23  is shown in  FIG. 3 ), whereby the seat can be smoothly slid along the lower rails. 
   The sliding-type automobile seat is provided with slide lock mechanisms for causing the seat to be locked at predetermined positions with respect to the lower rails  2   b . As shown in  FIG. 4 , the slide lock mechanisms include lock plates  4  arranged at side portions of the upper rails  2   a  (only one upper rail  2   a  and only one lock plate  4  are shown in  FIG. 4 ). An operating lever  5  for releasing the seat from a locked condition is provided so as to be bridged between the lock plates  4 . 
   Again referring to  FIGS. 3 and 4 , each of the lock plates  4  extends along the side portions of the substantially J-shaped members  20   a ,  20   b  of a corresponding upper rail  2   a . The lock plate  4  is pivotally supported, at the substantially middle portion of its longitudinal direction, to the side portions of the substantially J-shaped members  20   a ,  20   b  of the upper rail  2   a  by the support pin  40 , whereby the lock plate  4  is vertically swingable around the support pin  40 . Moreover, the lock plate  4  is formed, at its region adjacent a rear end portion thereof, with an elongated hole  41  vertically extending. A guide pin  42  projects from the side portion of the upper rail  2   a  and is inserted through the elongated hole  41  formed in the lock plate  4 , so that the vertical swinging movement of the lock plate  4  is guided along the elongated hole  41 . 
   The lock plate  4  is urged by a coil spring  43  so as to be always pulled upward at the rear end portion thereof. More particularly, the coil spring  43  is retained at one end portion thereof to a protruding piece  43   a  provided at a corresponding side frame section  1   a , and retained at the other end portion thereof to a protruding piece  43   b  bent from an upper edge of the lock plate  4 , whereby the coil spring  43  is provided between the side frame section  1   a  and the lock plate  4 . 
   Each of the slide lock mechanisms further includes first and second engaging means. The first engaging means comprises an engaging piece  44  projecting laterally from a lower edge of a corresponding lock plate  4  and a plurality of receiving holes  45  formed in the engaging piece  44 . The lower curved portions  20   a ′,  20   b ′ of the substantially J-shaped members  20   a ,  20   b  of the upper rail  2   a  are formed with slits  46 . The engaging piece  44  of the lock plate  4  projects so as to cross the inward bent flange  22   a  of the lower rail  2   b  through the slits  46 . 
   The second engaging means includes a plurality of protruding teeth  47  that are formed by making a lower portion of an inward bent flange  22   a  of a corresponding lower rail  2   b  into a concave/convex form. The protruding teeth  47  are releasably engaged with the receiving holes  45  formed in the engaging piece  44  of the lock plate  4 . 
   The operating lever  5  is formed in a substantially U-shape as viewed from above by causing a pipe material to be bent. Both end portions of the U-shaped operating lever  5  are flatly crushed and welded to forward portions of the lock plates  4 , whereby the operating lever  5  is connected to the lock plates  4 . As shown in  FIG. 1 , the operating lever  5  is bridged between the lock plates  4  and arranged under the seat cushion frame  1  with a forward portion thereof projecting forward of the seat. 
   In the slide lock mechanisms, the lock plates  4  are always urged upward at the rear end portions thereof by the coil springs  43  and the engaging pieces  44  are releasably meshed at the receiving holes  45  thereof with the protruding teeth  47  as shown in  FIG. 4 , whereby the upper rails  2   a  are locked with respect to the lower rails  2   b  so as to be unable to be slid relative to the lower rails  2   b . On the other hand, when the operating lever  5  is pulled up in such a direction that it approaches the seat cushion frame, namely, in such a direction as to be indicated in  FIG. 5  by an arrow, the rear end portions of the lock plates  4  are swung downward about the support pins  40  against the actions of the coil springs  43 , whereby the receiving holes  45  of the lock plates  4  are released from the engagement with the protruding teeth  47  of the lower rails  2   b , the engagement of the upper rails  2   a  with respect to the lower rails  2   b  is therefore released, and the seat is brought to a condition where it can be slidingly moved forward and rearward in the automobile. 
   In a case where the conventional automobile seat constructed as discussed above is assembled, it is necessary to cause the lock plates to be individually mounted to the upper rails. However, since the lock plates are previously welded to the both end portions of the substantially U-shaped operating lever, when such lock plates are individually mounted to the upper rails, mounting work of one of the lock plates to one of the upper rails will be interrupted by the other of the lock plates as well as the operating lever and a lot of time is taken for connecting of the operating lever to the lock plates and assembling the entire lock mechanisms. 
   Moreover, in the automobile provided with the seat constructed as discussed above, when any baggage, luggage, etc. is put on the floor surface of the automobile while being carelessly contacted with the operating lever, there is a possibility that the operating lever and/or the baggage, luggage, etc. will be damaged or deformed and the operating lever can not be properly operated. In this condition, if the operating lever is forcedly operated, there is a possibility that the operating lever will cause the baggage, luggage, etc. to be damaged or deformed. 
   The present invention has been made in view of the above-mentioned problems of the prior art automobile seat. 
   It is therefore an object of the present invention to provide a sliding-type automobile seat which facilitates connecting of an operating lever to slide lock mechanisms of the sliding-type automobile seat. 
   It is another object of the present invention to provide a sliding-type automobile seat which is simply constructed and in which even if any baggage, luggage, etc. is contacted with the operating lever of the automobile seat, the baggage, luggage, etc. and/or the operating lever of the automobile seat can be prevented from being damaged or deformed. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, there is provided a sliding-type automobile seat which comprises a seat cushion frame, a slide rail mechanism for allowing the seat to be slidingly moved, slide lock mechanisms for causing the seat to be releasably locked at predetermined positions, a substantially U-shaped operating lever for causing the seat to be released from a locked state, and connection mechanisms for causing both end portions of the substantially U-shaped operating lever to the slide lock mechanisms. The slide rail mechanism comprises a pair of parallel lower rails mounted on a floor surface of an automobile, and a pair of parallel upper rails attached to a lower portion of the seat cushion frame and slidably engaged with the pair of parallel lower rails. Each of the slide rock mechanisms comprises a lock member swingably mounted to a corresponding upper rail and urged upward at one end portion thereof by a spring, the lock member including first engaging means, and second engaging means provided at a corresponding lower rail. The first engaging means and the second engaging means are releasably engaged with each other, to thereby cause the seat to be locked at the predetermined positions. Each of the connection mechanisms comprises a connection member having means for stoppingly engaging the lock member. The means for stoppingly engaging the lock member is engaged with the lock member, whereby the operating lever is connected, via the connection mechanisms, to the slide rock mechanism by one-touch operation. 
   The means for stoppingly engaging the lock member may comprise a lower joint mounted on the connection member, and an upper joint fixed on the lower joint and extending along the lower joint in such a manner to allow a predetermined space the upper joint and the lower joint. The lock member may comprise a receiving piece for receiving one end portion of the lower joint, a holding-down piece for holding down the lower joint in the space between the lower joint and the upper joint, and a leaf spring having a first spring portion for causing the one end portion of the lower joint to be pressed against the receiving piece to interposingly hold the one end portion of the lower joint therebetween, and a second spring portion for pushing up the upper joint in the space to cause the holding-down piece to be pressed against the lower joint. 
   The upper joint may have a through-hole formed therein and the left spring may be provided with an engaging claw, the engaging claw being engaged with the through-hole. 
   The substantially U-shaped operating lever may include extending portions linearly extending laterally from the both end portions thereof, and support pins fitted in the extending portions of the operating lever, each of the support pins being connected to a connection member of a corresponding connection mechanism, coil springs for causing the operating lever to be urged upward are mounted at coiled portions thereof around the support pins, first end portions of the coil springs being stoppingly engaged with end portions of the support pins and second end portions of the coil springs being stoppingly engaged with connection members of the connection mechanisms, and stopper members provided around the support pins for engaging the connection members from above. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a seat cushion frame of a conventional sliding-type automobile seat; 
       FIG. 2  is a perspective view showing only one of side frame sections of the seat cushion frame shown in  FIG. 1 ; 
       FIG. 3  is a sectional view of a slide rail mechanism provided at the seat cushion frame shown in  FIG. 1 ; 
       FIG. 4  is a sectional view of the slide rail mechanism, taken along a line A-A in  FIG. 3 ; 
       FIG. 5  is a view showing a condition where the seat is released from a locked state; 
       FIG. 6  is a plan view showing an operating lever which is employed in a sliding-type automobile seat according to the present invention and in which a central portion of the operating lever has been left out of the illustration; 
       FIG. 7  is a view illustrating a condition where the operating lever shown in  FIG. 6  is connected to connection mechanisms; 
       FIG. 8  is a view that fully shows connection between the operating lever and the connection mechanisms; 
       FIG. 9  is an enlarged sectional view, taken along a line B-B in  FIG. 8 ; 
       FIG. 10  is a view that shows a condition where the operating lever shown in  FIG. 6  is connected to slide lock mechanisms via the connection mechanisms; 
       FIG. 11  is an enlarged view that fully shows the condition where the operating lever is connected to the slide lock members via the connection mechanisms; and 
       FIG. 12  is an enlarged sectional view that is of assistance in explaining a condition where the connection mechanisms are connected to the operating lever. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 6 to 12 , a sliding-type automobile seat according to an embodiment of the present invention will be discussed hereinafter. The sliding-type automobile seat according to the present invention is substantially similar to the conventional automobile seat shown in  FIGS. 1 to 5  except that a different operating lever  5 ′, different slide lock mechanisms, and connection mechanisms for facilitating connecting of the operating lever  5 ′ and the slide lock mechanisms are employed. Therefore, description of the respective components except the operating lever, the connection mechanisms and the slide lock mechanisms will not be repeated. 
   The slide lock mechanisms of the automobile seat according to the present invention comprises elongated lock members  4 ′ (see  FIG. 10  showing only one lock member  4 ′) that are different from the lock plates  4  of the conventional automobile seat, swingably mounted to the upper rails and provided with the first engaging means  44 ,  45  (see  FIGS. 3 ), and the second engaging means  47  (see  FIG. 3 ) provided at the lower rails. The first and second engaging means are releasably engaged with each other, whereby the seat is locked at predetermined positions. The operating lever  5 ′ serves as means to release the engagement between the first engaging means and the second engaging means and is connected to the lock members  4 ′ via longitudinal connection members  6  of the connection mechanisms (see  FIGS. 7 to 10  showing only one connection member  6 ). 
   The operating lever  5 ′ is formed in a predetermined shape by causing a pipe material to be bent. More particularly, as shown in  FIG. 6 , the operating lever  5 ′ comprises a substantially U-shaped body having a central axial grip-portion  5   a  which is to be gripped by an occupant on the seat when the operating lever  5 ′ is operated by the occupant, and left and right axial portions  5   b ,  5   b  linearly projecting laterally from both ends of the substantially U-shaped body. Annular flanges  53 ,  53  are provided around end regions of the left and right axial portions  5   b ,  5   b . Support pins  5   c ,  5   c  are press-fitted in the end regions of the left and right axial portions  5   b ,  5   b  of the operating lever  5 ′. 
   The support pins  5   c ,  5   c  comprise inner axial portions  50 ,  50  press-fitted in the end regions of the left and right axial portions  5   b ,  5   b  of the operating lever  5 ′, outer axial portions  51 ,  51  that are to be connected to the longitudinal connection members  6  of the connection mechanisms, and protruding end portions  52 ,  52  which project out of the outer axial portions  51 ,  51  and around which bush nuts or E-rings that will be discussed hereinafter are mounted. Moreover, slits  54  in which end portions of coil springs that will be discussed hereinafter are engagedly retained are formed in the protruding end portions  52 ,  52  by cutting deeply into the protruding end portions  52 ,  52 . 
   Stoppers  55 ,  55  are provided around the outer axial portions  51 ,  51  of the support pins  5   c ,  5   c . The stoppers  55 ,  55  are to be engaged with rising flanges of the longitudinal connection members  6  from above, when the connection members  6  are connected to the left and right axial portions  5   b ,  5   b  of the operating lever  5 ′. The stoppers  55 ,  55  comprises ring portions  55   a  fixedly mounted around the outer axial portions  51 ,  51 , and protruding portions  55   b  protruding laterally from upper edges of peripheries of the ring portions  55   a.    
   As shown in  FIGS. 7 to 9 , the left and right axial portions  5   b  of the operating lever  5 ′ are connected to forward end portions  6   a  of the longitudinal connection members  6  via the support pins  5   c  (respective components in connection with only one of the connection mechanisms are shown in  FIGS. 7 to 9 ). The connection mechanisms include lower joints  7  provided on rearward end portions  6   b  of the longitudinal connection members  6  thereof and engagedly connected to the lock members  4 ′ that are mounted to the upper rails, and upper joints  8  fixed onto the lower joints  7 . The upper joints  8  extend rearward in such a manner to allow spaces to be produced between the lower joints  7  and the upper joints  8  and are engagedly connected to the lock members  4 ′. 
   As shown in  FIG. 7 , the longitudinal connection members  6  are formed in substantially L-shapes and include intermediate portions  6   c  extending between the forward end portions  6   a  and the rearward end portions  6   b  so as to have slopes descending from the forward end portions  6   a . The support pins  6   c  of the operating lever  5 ′ are penetrated through the forward end portions  6   a  of the longitudinal connection members  6 , whereby the U-shaped operating lever  5 ′ is connected to the longitudinal connection members  6 . Moreover, as shown in  FIG. 8 , each of the longitudinal connection members  6  is formed in a substantially U-shape in cross-section and includes a pair of spaced apart rising flanges  6   c ,  6   d . In upper edge regions of the rising flanges  6   d  of the connection members  6  which are located at the forward end portions  6   a  of the connection members  6 , receiving recesses  6   e  for engagingly receiving the protruding portions  55   b  of the stoppers  55  of the operating lever  5 ′ are formed so as to have widths larger than those of the protruding portions  55   b  (widths measured in circumferential directions of the ring portions  55   a  of the stoppers  55 ). 
   As shown in  FIGS. 10 and 11 , the lower joints  7  comprise forward end portions  7   a  fixedly welded onto inner surfaces of bottoms of the connection members  6 , rearward end portions  7   c  located at positions higher than the forward end portions  7   a , and longitudinal intermediate portions  7   b  extending between the forward end portions  7   a  and the rearward end portions  7   c . The longitudinal intermediate portions  7   b  extend slightly downward relative to the rear end portions  6   b  of the connection members  6 , further extend horizontally and still further extend upward to the rearward end portions  7   c.    
   The upper joints  8  are formed in substantially U-shapes in cross-section and comprises forward end portions  8   a  fixedly welded onto the forward end portions  7   a  of the lower joints  7 , rear end portions  8   c  rising up, and intermediate portions  8   b  interconnecting the forward end portions  8   a  and the rear end portions  8   c , and extending from the forward end portions  8   a  along the lower joints  7  so as to be vertically spaced apart from the lower joints  7  at predetermined intervals G ( FIG. 7 ). Moreover, the intermediate portions  8   b  are formed with elongated through-holes  8   d  of substantially rectangle-shapes at regions thereof which are adjacent the rearward end portions  8   c  of the upper joints  8 . 
   The elongated lock members  4 ′ comprise longitudinal plate-shaped portions, spaced apart side portions protruding forward from forward ends of the longitudinal plate-shaped portions, receiving pieces  48   a  provided at forward ends of the spaced apart side portions and bridged between lower regions of the spaced apart side portions, and holding-down pieces  48   b  provided at regions of the spaced apart side portions that are adjacent the longitudinal plate-shaped portions, the holding-down pieces  48   b  being bridged between the lower regions of the spaced apart side portions. When the connection mechanisms connected to the operating lever  5 ′ are connected to the slide lock mechanisms, the receiving pieces  48   a  are adapted to engagingly receive the rear end portions  7   c  of the lower joints  7  and the holding-down pieces are inserted in the intervals G between the intermediate portions  7   b  of the lower joints  7  and the upper joints  8  and hold down the longitudinal intermediate portions  7   b  of the lower joints  7 . The receiving pieces  48   a  and the holding-down pieces  48   b  are formed into substantially U-shapes in cross-section. 
   Moreover, elongated leaf springs  9  are attached to the lock members  4 ′. The leaf springs  9  are arranged between the spaced apart side portions of the elongated lock members  4 ′ and comprise bodies having substantially U-shaped in cross-section. The substantially U-shaped bodies comprise first spring portions  9   a  for pressing the rearward end portions  7   c  of the lower joints  7  against the receiving pieces  48   a  of the lock members  4 ′ and interposedly holding the rearward end portions  7   c  of the lower joints  7  therebetween, and second spring portions  9   b  inserted in the intervals G between the lower joints  7  and the upper joints  8  for pushing the upper joints  8  upward to cause the holding down pieces  48   b  to be pressed against the longitudinal intermediate portions  7   b  of the lower joints  7 . 
   The first spring portions  9   a  and the second spring portions  9   b  are formed by bottom surfaces of the substantially U-shaped bodies of the leaf springs  9 . Engaging claws  9   c  of substantially triangle-shapes are provided on the second spring portions  9   b . Moreover, spring-supporting members  49   a  are arranged between the spaced apart side portions of the lock members  4 ′ and swingably supported to the lock members  4 ′ via support pins  49   b . The leaf springs  9  are also swingably supported to the lock members  4 ′ via the support pins  49   b . Moreover, elongated return springs  49  are attached at one end portions thereof to the spring-supporting members  49   a  by pins  49   c . Therefore, the return springs  49  are also swingable together with the spring-supporting members  49   a . The return springs  49  serve to urge the connection members  6  in such a direction to cause the connection members  6  to be locked with respect to the lock members  4 ′, when the connection members  6  connected to the U-shaped operating lever  5 ′ are connected to the lock members  4 ′ for assembling. Though not shown, the lock members  4 ′ are attached to the upper rails by causing the pins  49   c  to be penetrated through the upper rails and then causing the pins  49   c  to be riveted over surfaces of the upper rails. The lock members  4 ′ are urged upward by the coil springs (not shown) in the same manner as the lock plates  4  of the conventional seat are done. Moreover, though not shown, the lock members  4 ′ are provided at the longitudinal plate-shaped portions thereof with the engaging pieces  44  ( FIG. 3 ) having the engaging holes  45  (see  FIG. 3 ) with which the protruding teeth  47  (see  FIG. 3 ) of the lower rails are engaged, like the lock plates  4  of the conventional seat. 
   The lock members  4 ′ are individually mounted to the upper rails and the operating lever  5 ′ are then connected via the connection mechanisms to the lock members  4 ′, so that the connecting of the operating lever  5 ′ to the slide lock mechanisms is carried out by one-touch operation with utilizing the connection mechanisms constructed as discussed above. 
   The connecting of the operating lever  5 ′ to the slide lock mechanisms through the connection mechanisms connected to the operating lever  5 ′ is carried out as follows. As shown in  FIGS. 10 and 11 , the connection members  6  connected to the left and right axial portions of the operating lever  5 ′ are engaged at the rearward end portions  7   c  of the lower joints  7  thereof with the receiving pieces  48   a  of the lock members  4 ′, and the holding-down pieces  48   b  of the lock members  4 ′ are inserted into the gaps G between the longitudinal intermediate portions  7   b  of the lower joints  7  and the upper joints  8  while being applied onto the longitudinal intermediate portions  7   b  of the lower joints  7  and engaged at the through-holes  8   d  of the upper joints  8  with the engaging claws  9   c  of the leaf springs  9 . At this time, the rearward end portions  7   c  of the lower joints  7  are pressed against the receiving pieces  48   a  of the lock members  4 ′ by the first spring portions  9   a  of the leaf springs  9 , whereby the rearward end portions  7   c  of the lower joints  7  are interposedly held between the first spring portions  9   a  of the leaf springs  9  and the receiving pieces  48   a . Moreover, the upper joints  8  are pushed up in the gap G between the upper joints  8  and the lower joints  7  by the second spring portions  9   b  of the leaf springs  9 , to thereby cause the holding-down pieces  48   b  of the lock members  4 ′ to be pressed against the longitudinal intermediate portions  7   b  of the lower joints  7 . Thus, the connecting of the operating lever  5 ′ to the slide lock mechanisms through the connection mechanisms can be easily performed by one-touch operation. Therefore, it is possible to facilitate speedy assembling work of the entire lock mechanisms. 
   In addition to the urging by the leaf springs  9 , the through-holes  8   d  formed in the regions of the upper joints  8  which are adjacent the rearward end portions Sc of the upper joints  8 , and the engaging claws  9   c  provided on the second spring portions  9   b  of the leaf springs  9  are engaged with each other, whereby the connection members  6  connected to the left and right axial portions of the operating lever  5 ′ can be securely connected to the lock members  4 ′ so as not to be removed from the lock members  4 ′. 
   The operating lever  5 ′ is connected at the left and right axial portions thereof to the forward ends  6   a  of the connection members  6  by the support pins  5   c  with protruding portions  55   b  of the stoppers  55  thereof being received in the receiving recesses  6   e  of the connection members  6 . The entire operating lever  5 ′ is urged upward by coil springs  56 . Thus, the operating lever  5 ′ is adapted to be pivotable downward of the connection members  6  and able to be pulled up in order that the lock members  4 ′ are released from locked states. 
   As shown in  FIGS. 8 ,  9  and  12 , the coil springs  56  are stretched between the support pins  5   c  and the connection members  6  by causing coil portions  56   a  of the coil springs  56  to be mounted around the outer axial portions  51  of the support pins  5   c  penetrating the rising flanges  6   c ,  6   d  of the connection members  6 , causing first end portions  56   b  of the coil springs  56  to be engagedly fitted in the slits  54  of the support pins  5   c , and causing the second end portions  56   c  of the coil springs  56  to be engagedly fitted in spring receiver sleeves  6   f  that are provided on the inner surfaces of the bottoms of the connection members  6  (only one of the connection members  6  and only one of the support pins  5   c  of the operating lever  5 ′ are shown in  FIGS. 8 ,  9  and  12 ). Incidentally, the bush nuts or E-rings  57  are mounted on the protruding axial portions  52  of the support pins  5   c , whereby the support pins  5   c  are prevented from being disconnected from the connection members  6 . 
   The entire operating lever  5 ′ is adapted to be able to be pivoted downward against the actions of the coil springs  56  until the protruding portions  55   b  of the stoppers  55  are abutted against edges of the receiving recesses  6   e  of the connection members  6  (see  FIG. 10 ), so that even if any baggage, luggage, etc. is contacted with the operating lever  5 ′ from above, the baggage, luggage, etc and/or the operating lever  5 ′ can be prevented from being damaged or deformed. Moreover, it is possible to easily pull the operating lever  5 ′ up in order that the lock members  4 ′ are released from the engagement with the lower rails. 
   The terms and expressions which have been employed herein are used as terms of description, not of limitation. There is no intention in the use of such terms and expressions of excluding any equivalents of the features described or any portions thereof. It is recognized, however, that various modifications are possible within the scope of the invention claimed.