Latch releasing mechanism for use in a front seat of a vehicle

A front seat includes a seat cushion and a reclining back cushion, and is so arranged as to move back and forth between forward and retracted positions. The seat is temporarily released from the latched position for moving the seat towards the most forward position for facilitating movement of the rear seat passengers into and out of the vehicle. Thereafter, the front seat is again returned and latched in an original position by the operation of latch releasing mechanism employed in the front seat.

The present invention relates to a front seat of a two door vehicle, and 
more particularly, to a latch releasing mechanism for temporarily 
releasing the front seat from a latched position to move the front seat 
towards the most forward position and to tilt a reclining back cushion 
towards the front for facilitating movement of the rear seat passengers of 
into and out from the vehicle. 
Usually, the two door vehicle has a shiftable front seat which is so 
arranged as to move back and forth between forward and retracted positions 
by a movement of a carrier member supporting the seat slidably on a rail 
member fixedly provided on the body of the vehicle. The seat includes a 
seat cushion and a reclining back cushion pivotally connected to the seat 
cushion for tilting the back cushion towards and away from the seat 
cushion. The carrier member is coupled with a latch means for maintaining 
the seat in a required position between the forward and retracted 
positions. The latch releasing mechanism is normally combined with the 
latch means for temporarily releasing the latch means to move the front 
seat towards the most forward position thereof for enabling the rear seat 
passengers to move into and out of the vehicle. Thereafter, the front seat 
is again returned to the original position. 
One conventional latch releasing mechanism is disclosed in U.S. Pat. No. 
3,931,995 of Tomiji Arai, in which the various components constituting the 
latch releasing mechanism are disposed on the carrier member in a spaced 
relation to each other, so that the latch releasing mechanism occupies a 
large space on the carrier member. Furthermore, since the components 
thereof are provided independently on the carrier member by different 
mounting means, such as different shafts, a large number of manufacturing 
steps are necessary for constructing the latch releasing mechanism, while 
at the same time, the manufacturing cost therefor are accordingly 
increased. 
Accordingly, a primary object of the present invention is to provide a 
latch releasing mechanism which has a simple construction, and which is 
easy to operate for efficient shifting of the front seat including the 
seat cushion and the reclining cushion. 
Another important object of the present invention is to provide a latch 
releasing mechanism of the above described type which is compact in size, 
and can be readily incorporated into seats of the reclining type at low 
cost. 
In order to accomplish these and other objects, the latch releasing 
mechanism of the present invention comprises a latch release blade 
pivotally mounted on the carrier member for movement towards and away from 
a predetermined position at which the latch release blade releases the 
latch mechanism. The latch release blade is moved to said predetermined 
position upon movement of the back cushion when the back cushion is 
tilted. The latch release blade further has a detent recess therein. 
A manually operable lever, pivotally mounted on the carrier member, has a 
trigger arm engagable with the latch release blade for movement of the 
latch release blade towards the predetermined position upon movement of 
the manually operable lever in a predetermined direction. 
A lock member pivotally mounted on the manually operable lever, has an 
engaging portion which is engagable with the detent recess when the latch 
release blade is moved to the predetermined position. 
The latch releasing mechanism of the present invention further comprises 
means for biasing the lock member in a predetermined direction to lock the 
latch release blade in the predetermined position when the latch release 
blade is moved to the predetermined position, and detent release means 
provided on the rail for moving the lock member in an opposite direction 
to the predetermined direction to unlock the latch release blade when the 
lock member is moved by the detent release means as a result of movement 
of the carrier member towards the retracted position.

Before the description of the present invention proceeds, it is to be noted 
that like parts are designated by like reference numerals throughout the 
accompanying drawings. 
Referring to FIG. 1, a front seat S employed in a vehicle, especially of 
the two door type, includes a seat cushion 2 on which the driver or the 
passanger sits and a reclining back cushion 4 pivotally connected to the 
seat cushion 2 through a reclining mechanism 6 of a known type which is 
provided for adjusting the angle of the back cushion 4 with respect to the 
seat cushion 2 and also for tilting the back cushion 4 towards the seat 
cushion 2. The reclining mechanism 6 includes a knob 8 which is manually 
moved in one direction for freeing the back cushion 4 for rotation about 
the reclining mechanism 6 to a desired angle with respect to the seat 
cushion 2, and is moved in opposite direction to said one direction for 
firmly fixing the back cushion 4 at the desired angle. 
The seat cushion 2 is firmly connected to a carrier member 12 which is 
slidably mounted on a rail 14 firmly connected to the body of the vehicle. 
A projection 16 is provided at one end portion, namely the rear end 
portion, of the carrier member 12 while a projection 18 is provided at one 
end portion, namely the front end portion, of the rail 14. A spring 20 is 
biased between the projections 16 and 18 for urging the carrier member 12 
in the left-hand direction, namely the front direction with respect to the 
vehicle. 
The carrier member 12 and rail 14 are preferably provided in two or more 
pairs, for example, two pairs which are provided in parallel relation to 
each other for slidably moving the seat S back and forth between forward 
and retracted positions. FIG. 1 shows only one carrier member 12 and rail 
14, which are provided with a latch releasing mechanism 30 of the present 
invention described later. 
A projection 10 projecting from the reclining mechanism 6 at approximately 
opposite side to the side where the back cushion 4 is provided rotates 
about the reclining mechanism 6 in relation to the rotation of the back 
cushion 4 about the reclining mechanism 6. A connecting rod 22 has one end 
portion connected to the projection 10, while the other end is hooked to 
the latch releasing mechanism 30 for transmitting to the latch releasing 
mechanism 30, the movement of the projection 10, and more particularly, 
the movement of the projection 10 in the direction indicated by an arrow 
A. In other words, the connecting rod 22 is shifted in the direction A 
upon tilting the back cushion 4 towards the front, while the returning of 
the back cushion 4 to the original position will not cause transmission of 
any movement to the latch releasing mechanism 30, but merely loosen the 
hooked condition between the rod 22 and the latch releasing mechanism 30. 
Referring to FIGS. 2 and 3, the latch releasing mechanism 30 of the present 
invention comprises a blade member 32 pivotally mounted at an intermediate 
portion thereof, by a shaft 34, on the top of the carrier member 12 for 
movement between an engaged position and a disengaged position. The blade 
member 32 has on one end portion 32a a projecting edge 36 capable of being 
hooked to the other end of the rod 22 while the other end portion 32b has 
a curved arm 32c. It is to be noted that the curved arm 32c extends below 
the top plane of the carrier member 12, as best shown in FIG. 5, so that 
the end portion of the curved arm 32c will come into contact with the rail 
14. The rail 14, along the side face thereof, is provided with number of 
openings 14a for receiving therein the end portion of the curved arm 32c. 
A spring 35 is connected between the carrier member 12 and the blade member 
32 for urging the blade member 32 to rotate a counterclockwise direction, 
so as to position and maintain the blade member 32 in the engaged position 
where the curved arm 32c is inserted into one of the openings 14a. When 
the blade member 32 is turned to the engaged position, the carrier member 
12 is latched in a position with respect to the rail 14, and thus the seat 
S is locked in a position with respect to the rail 14. The disengagement 
of the curved arm 32c from the opening 14a turns the blade member 32 to 
the disengaged position. When the blade member 32 is in the disengaged 
position, the carrier member 12 is unlatched from the rail 14, and thus, 
the seat S is in a condition capable of sliding along the rail 14 between 
the forward and retracted positions. The disengaged position of the blade 
member 32 can be effected by the movement of the rod 22 in the direction A 
as a result of tilting of the back cushion 4 towards the seat cushion 2, 
as shown in FIG. 1, or otherwise, by the movement of a manually operable 
lever 40 described hereinbelow. 
The lever 40, positioned on top of the blade member 32, is pivotally 
mounted at one end portion 40a thereof, by the shaft 34, on the carrier 
member 12. The other end portion 40b of the lever 40 extends along the 
carrier member 12 and terminates in front of the seat S (FIG. 1) for 
manual operation of the lever 40. The lever 40, at the end portion 40a, is 
provided with a trigger projection 42 extending in parallel relation to 
the shaft 34 towards the carrier member 12. It is to be noted that the 
lever 40 is normally biased by a suitable spring means such as a coil 
spring (not shown) for urging the lever 40 to rotate in a direction 
indicated by an arrow E and to terminate in the position shown in FIG. 2 
by an engagement of the lever 40 and the member 12. 
Upon manual rotation of the lever 40 about the shaft 34 in the direction 
indicated by the arrow D, the trigger projection 42 comes into contact 
with the right-hand side edge of the blade member 32, and a further 
rotation of the lever 40 in the direction D rotates the blade member 32 in 
a clockwise direction against the biasing force of the spring 34, so that 
the blade member 32 is turned to the disengaged position. 
A lock member 50, positioned on top of the lever 40, is pivotally mounted 
at approximately the central portion thereof, by a shaft 52, on the end 
portion 40a of the lever 40. The lock member 50 has three arms 50a, 50b 
and 50c extending from the center thereof. The first arm 50a has an 
engaging edge 54 extending parallel to the shaft 52 towards the carrier 
member 12 for engagement with the blade member 32. The second arm 50b 
extending approximately at right angles to the first arm 50a is formed 
with a contact surface 56 extending in parallel to the shaft 52 towards 
the rail 14 for the sliding contact with a projection 60 which is fixedly 
provided on the side of the rail 14, while the third arm 50c extending in 
approximately the opposite direction to the first arm 50a has a recess 58 
for connecting thereto one end of a spring 62. The other end of the spring 
62 is connected with the lever 40 for urging the entire lock member 50 in 
a clockwise direction. 
The engagement and disengagement between the engaging edge 54 and the blade 
member 32 is carried out in a manner described hereinbelow. The blade 
member 32 has a detent recess 32d in the left-hand side edge thereof 
adjacent the shaft 34. When the blade member 32 is in the engaged 
position, as shown in FIG. 2, where the curved arm 32c is inserted into an 
opening 14a, the engaging edge 54 on the lock member 50 is located 
adjacent the detent recess 32d, as shown in FIG. 2, the engaging edge 54 
being in an unlocked position with respect to the detent recess 32d. 
On the other hand, when the blade member 32 is turned to the disengaged 
position, as shown in FIG. 4, as a result of tilting of the back cushion 4 
towards the seat cushion 2, the blade member 32 rotates so that the 
engaging edge 54 of the lock member 50 comes into contact with the detent 
recess 32d, and thus, the engaging edge 54 is in a locked position with 
respect to the detent recess 32d. However, when the blade member 32 is 
turned to the disengaged position, as shown in FIGS. 6 and 7, as a result 
of manual rotation of the lever 40 in the direction D, the contact of the 
edge 54 and the recess 32d is released. 
The description hereinbelow is directed to the movement of the latch 
releasing mechanism 30 of the present invention in relation to the 
movement of the seat S for accommodating passenger in a rear seat (not 
shown) of the vehicle. 
First, the knob 8 is manually in one direction to permit tilting of the 
back cushion 4 towards the seat cushion 2, as shown in FIG. 1. Thereupon, 
the rod 22 is simultaneously shifted in the direction A to rotate the 
blade member 32 in a clockwise direction. Thus, the blade member 32 is 
turned from the engaged position (FIG. 2) to the disengaged position and 
the biasing force of the spring 20 moves the seat S in the forward 
direction. Accordingly, the surface 56 moves out of engagement with the 
projection 60, and the lock member 50 rotates in the clockwise direction 
due to the biasing force of the spring 62. As result, the edge 54 moves 
into the recess 32d, and the blade member 32 is maintained at the 
disengaged position, and the seat S is moved to the most forward position 
(FIG. 4). In this condition, the passenger may simply move into the rear 
seat of the vehicle through a wide open space formed behind the front seat 
S which has been moved to the most forward position. Thereafter, the back 
cushion 4 is rotated about the reclining mechanism 6 in a clockwise 
direction to return to the original position. It is to be noted that the 
returning of the back cushion 4 will not cause any movement of the latch 
releasing mechanism 30, so that the blade member 32 is still maintained in 
the disengaged position. Therefore, the seat S can be slidingly moved 
along the rail 14 towards the retracted position. After the seat S is 
moved towards the retracted position a predetermined distance, the contact 
surface 56 comes into contact with the projection 60 projecting from the 
rail 14 at an intermediate portion thereof, so that the lock member 50 is 
rotated in a counterclockwise direction towards the unlocked position, 
thus, allowing the blade member 32 to turn to the engaged position, as 
shown in FIG. 2. 
Then, the passenger in the front seat S may adjust the position of the seat 
by turning the end portion 40b of the lever 40 in the direction D, as 
shown in FIGS. 6 and 7, for turning the blade member 32 towards the 
disengaged position. Thereupon, the passenger moves the seat S to the 
position where he desires, and then, returns the end portion 40b of the 
lever 40 in the original position to return the blade member 32 to the 
locked position, as shown in FIG. 8. 
Referring to FIGS. 9 to 13, there is shown a latch releasing mechanism 130 
which is another embodiment of the latch releasing mechanism 30 described 
above. The latch releasing mechanism 130 comprises a blade member 132 of a 
similar type as described above pivotally mounted at an intermediate 
portion thereof, by a shaft 134, on top of the carrier member 12 for 
movement between an engaged position and a disengaged position. The blade 
member 132 has on one end portion 132a a projecting edge 136 capable of 
being hooked with the other end of the rod 22, while the other end portion 
132b has a curved arm 132c. Instead of having the curved arm 132c come 
into direct contact with the rail 14, as described above, the curved arm 
132c comes into contact with an "L" shaped cross sectional bar 170 which 
is fixedly provided on the rail 14 in parallel relation thereto. One end 
of the bar 170 terminates at an intermediate position between the opposite 
ends of the rail 14 and the other end thereof terminates at approximately 
the rear end of the rail 14. The side surface of the bar 170 which is 
contacted by the curved arm 132c has a plurality of openings 170a in 
alignment with the rail 14 for receiving therein the end portion of the 
curved arm 132c. Since the rail 14 in this embodiment is not directly 
engaged by the curved arm 132c, because it is not necessary to form the 
openings in the rail 14 for the engagement by the curved arm 132c, it will 
be understood that the strength of the rail 14 for supporting the carrier 
member 12, as well as the seat S, is further increased. Furthermore, the 
presence of the bar member 170 reinforces the rail 14. 
A spring 135 extends between the carrier member 12 and the blade member 132 
for urging the blade member 132 to rotate in a counterclockwise direction, 
so as to position and maintain the blade member 132 in the engaged 
position where the curved arm 132c is inserted into one of the openings 
170a. The disengagement of the curved arm 132c from the opening 170a turns 
the blade member 132 to the disengaged position. The disengaged position 
of the blade member 132 can be effected by the movement of the rod 22 in 
the direction A as a result of tilting of the back cushion 4 towards the 
seat cushion 2, in the same manner as described above, or otherwise, by 
the movement of a manually operable lever 140 described hereinbelow. 
The lever 140, positioned on top of the blade member 132, is pivotally 
mounted at approximately the central portion thereof, by the shaft 134, on 
the carrier member 12. One end portion 140a of the lever 140 extends in a 
direction approximately perpendicular to the carrier member 12 terminates 
at the side of the seat S for manual operation of the lever 140. The other 
end portion 140b, is provided with a trigger projection 142 extending in 
parallel relation to the shaft 134 towards the carrier member 12. It is to 
be noted that the lever 140 is normally biased by a spring 137 extending 
between the lever 140 and the carrier member 12 for urging the lever 140 
to rotate in a direction indicated by the arrow E and to terminate in a 
position shown in FIGS. 10 and 13 by the engagement of the lever 140 and 
the frame member 100. 
Upon manual rotation of the lever 140 about the shaft 134 in a direction 
indicated by the arrow D, the trigger projection 142 comes into contact 
with the right-hand side edge of the blade member 132, and a further 
rotation of the lever 140 in the direction D rotates the blade member 132 
in a clockwise direction against the biasing force of the springs 135 and 
137, so that the blade member 132 is turned to the disengaged position. 
The lock member 150 is pivotally mounted at approximately the end portion 
thereof, by a shaft 152, on the end portion 140b of the lever 140. The 
lock member 150 has an arm 150a extending in a horizontal plane below the 
top plane of the carrier member 12 and which is on a perpendicularly 
extending engaging portion 150b (FIG. 11). The length of the arm 150a is 
sufficient to cause it to come into contact with the side surface of the 
bar 170, while the engaging surface 150b is provided for the engagement 
with the blade member 132. A spring 162 is connected between the lock 
member 150 and the lever 140 for urging the lock member 150 to rotate in a 
clockwise direction. 
The engagement and disengagement between the engaging surface 150b and the 
blade member 132 is carried out in such a manner described hereinbelow. 
The blade member 132 has a detent recess 132d in the left-hand side edge 
thereof adjacent the shaft 134. When the blade member 132 is in the 
engaged position, as shown in FIG. 10, where the curved arm 132c is 
inserted into opening 170a, the engaging surface 150b is positioned 
adjacent the detent recess 132d, that is, at the side of the detent recess 
132d when viewed in FIG. 10, because of the rotation of the lock member 
150 in the direction indicated by the arrow F caused by the contact 
between the arm 150a and the side surface of the bar 170. Accordingly, the 
engaging surface 150b is in an unlocked position with respect to the 
detent recess 132d. 
On the other hand, when the blade member 132 is turned to the disengaged 
position, as shown in FIG. 12, as a result of tilting of the back cushion 
4 towards the seat cushion 2, and furthermore, as a result of movement of 
the seat S to the forward position past the forward end of the bar 170, 
the lock member 150 is rotated by spring 162 in a direction opposite to 
the direction F, so that the engaging surface 150b moves into the detent 
recess 132c, and thus, the engaging surface 150b is in a locked position 
with respect to the detent recess 132d. 
The description hereinbelow is directed to the movement of the latch 
releasing mechanism 130 of the present invention in relation to the 
movement of the seat S for accommodating a passenger in the rear seat (not 
shown) of the vehicle. 
First, the knob 8 is manually moved in one direction to tilt the back 
cushion 4 towards the seat cushion 2, in the same manner as described 
before. Thereupon, the rod 22 is simultaneously shifted in the direction A 
to rotate the blade member 132 in a clockwise direction. Thus, the blade 
member 132 is turned to the disengaged position and is maintained at the 
disengaged position by the rod 22 continually holding the blade member 132 
in the disengaged position. Accordingly, the biasing force of the spring 
20 moves the seat S towards the most forward position. In the meantime, 
when the lock member 150 moves past the forward end of the bar 170, the 
lock member 150 rotates in a direction opposite to the direction F to the 
locked position where the engaging surface 150b engages in the detent 
recess 132d. During this condition, the passenger may simply move into the 
rear seat of the vehicle through a wide open space formed behind the front 
seat S which has been moved to the most forward position. Thereafter, the 
back cushion 4 is rotated about the reclining mechanism 6 in a clockwise 
direction to return to the original position. It is to be noted that the 
returning of the back cushion 4 will not effect any movement of the latch 
releasing mechanism 130 since the blade member 132 is maintained in the 
disengaged position by the lock member 150 which is in the locked 
position. Therefore, the seat S can be slidingly moved along the rail 14 
towards the retracted position. After the seat S is moved towards the 
retracted position a predetermined distance, the arm 150a comes into 
contact with the edge of the bar 170 so that the lock member 150 is 
rotated in the direction F towards the unlocked position, thus, allowing 
the blade member 132 to turn to the engaged posotion. 
Then, the passenger in the front seat S may adjust the position of the seat 
by turning the end portion 140a of the lever 140 in the direction D for 
turning the blade member 132 towards the disengaged position. Thereupon, 
the passenger moves the seat S to the position which he desires, and then, 
returns the end portion 140a of the lever 140 to the original position to 
turn the blade member 132 to the locked postion, as shown in FIG. 10. 
It is to be noted that the latch releasing mechanism 30 or 130 of the 
present invention may be provided with a frame member or substrate such as 
shown in FIG. 10 designated by a reference number 100 for pivotally 
mounting the blade member and the lever, so that the carrier member 12 can 
be easily provided with the latch releasing mechanism of the present 
invention. 
As is apparent from the foregoing description, the latch releasing 
mechanism of the present invention can be made in a comparatively small 
size, since the various components, such as the blade member, lever and 
lock member are provided one over the other. Furthermore, since the blade 
member and the lever are mounted on the carrier member by only one shaft, 
not only is the manufacturing facilitated, but also the manufacturing cost 
is reduced. 
Although the present invention has been fully described by way of examples 
with reference to the accompanying drawings, it is to be noted that 
various changes and modifications will be apparent to those skilled in the 
art. Therefore, unless such changes and modifications depart from the 
scope of the present invention, they should be construed as being included 
therein.