Adjusting mechanism for use on the armrest of a vehicle's seat

An improved armrest adjusting mechanism for use on a vehicle's seat is provided with a slide board housed in an adjusting bracket. The slide board has a dentate portion having a plurality of dents which are in retaining engagement with a pivotal retaining ratchet secured to the adjusting bracket. The adjusting bracket can only be pulled upwardly in adjustment so as to make the armrest extended. The lowering of the armrest can be easily effected by pulling the adjusting bracket all the way up its top end, taking the retaining ratchet out of the moving path of the dentate portion of the slide board with the ratchet retained in place by a locking pole which is brought to the bottom of an elliptic through hole when the adjusting bracket is pulled to its top end. Then, the adjusting bracket is pushed downwardly and the retained locking pole will be pushed out of retaining engagement with the spring biased retaining ratchet and the locking pole moves to the top end of the elliptic through hole. The retaining ratchet resumes its retaining engagement with the dents of the dentate portion of the slide board so as to complete the adjustment.

BACKGROUND OF THE INVENTION 
The present invention relates to an improved adjusting mechanism for 
variation of the position of the armrest of a vehicle's seat. The 
adjusting mechanism is provided with a sliding board slidably received in 
an adjusting bracket. The sliding board which is fixed to the vehicle has 
a dentate portion engaged with a retaining ratchet secured to the 
adjusting bracket so that the adjusting mechanism can only be pulled 
upwardly to make the armrest extend in adjustment. To make the adjusting 
mechanism move down to lower the armrest, the adjusting mechanism must be 
pulled all the way up to its top limit, taking the retaining ratchet out 
of engagement with the dentate portion of the slide board with the ratchet 
held by a locking pole. The adjusting mechanism is then pushed downwardly 
to set the retained ratchet and the locking pole free so as to effect 
downward adjustment of the armrest on the adjusting mechanism. 
The armrest of a vehicle or a public bus seat is usually not adjustable, so 
the hands of passengers on a bus having different physical sizes generally 
do not fit well in a seat, making passengers feel uncomfortable. To 
overcome such a problem, a prior art adjustable armrest, as shown in FIG. 
1, was developed and applied to vehicle seats. 
This prior art armrest has the following drawbacks in practical operation: 
1. Such conventional armrest adjusting mechanism must be operated by two 
hands at the same time to vary the height of the armrest with one hand 
actuating the control lever to one direction and the other hand varying 
the position of the armrest. It is very inconvenient for a handicapped 
person to make the adjustment. 
2. The conventional armrest adjusting mechanism is operated in a relatively 
tedious manner and is hard to handle by children. 
3. The control lever is easily damaged so as to make a normal adjustment 
difficult frequently. 
SUMMARY OF THE INVENTION 
The primary object of the present invention is to provide an improved 
adjusting mechanism for varying the position of the armrest of a vehicle 
seat at will simply by pulling the armrest upward when the armrest is to 
be set at a higher position and by pulling the armrest to the top limit 
and then pushing downward to a lower position when the position of the 
armrest is to be lowered down. 
Another object of the present invention is to provide an improved armrest 
adjusting mechanism which enables a person to make adjustment of the 
height of the armrest on the adjusting mechanism of a vehicle seat by 
simply pulling up or pushing down the armrest with one hand in relation to 
the fixed sliding board. 
One further object of the present invention is to provide an improved 
armrest adjusting mechanism having a retaining hook which can be easily 
released by simply pulling up or pushing down the armrest directly for 
adjustment of the position of the armrest, effectively reducing the chance 
of malfunction resulting from improper operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 2, the armrest adjusting mechanism of the present 
invention is mainly comprised of an adjusting bracket 1, a cover 2, a 
slide board 3, fixed to a vehicle (not shown) a locking pole 4, a 
retaining ratchet 5 and a bias spring 6. 
The adjusting bracket 1 made in the form of an armrest engaged to the top 
of adjusting bracket 1 is shown in FIG. 3, has a hollow interior for 
housing the slide board 3 fixed to the vehicle. An elongated groove 15 is 
disposed on a securing face 11, to which the cover 2 is removably 
attached, to the adjusting bracket 1. At the center of the groove 15 is 
disposed an elliptic through hole 14, as shown in FIG. 2. On the edge of 
the elongated groove 15 and right next to the elliptic hole 14 is disposed 
a curve-faced block 13. On the opposite face of the elongated groove 15 
and near the opposite of the block 13 is defined a shaft hole 12. 
Secured to the adjusting bracket 1 is the cover 2 having a square hole 21 
disposed near one end thereof and a hole 22 in alignment with the shaft 
hole 12. An elliptic hole 23 in correspondence to the through hole 14 is 
disposed at the center of the cover 2. p The slide board 3 has a central 
opening 30 having a dentate portion 31 with which the pivotal retaining 
ratchet 5 on adjusting bracket 1 can be engaged to slide board 3 for 
locking purpose. At one end of the dentate portion 31 is disposed a 
protrude shoulder 32. To the opposite end of the dentate portion 31 is 
secured an extended limiting member 33 by a screw. 
The bolt-like locking pole 4 is led through the elliptic through hole 14 of 
the adjusting bracket 1 and further the slide board 3 and is slidably 
engaged in through hole 14 by a screw 9 extending through slot 23 fastened 
to pole 4. 
The retaining ratchet 5 is pivotally engaged with a shaft 51 which extends 
through the shaft hole 12 of the adjusting bracket 1 and the opening 30 of 
the slide board 3 and the retaining ratchet 5 and the bias spring 6 and 
the hole 22 of the cover 2 sequentially. The retaining ratchet 5 has a 
retaining portion 53 and a curved sliding portion 52. The bias spring 6 is 
approximately V-shaped and has one end hooked inwardly. 
In assembly, the slide board 3 is first inserted into the hollow interior 
of the adjusting bracket 1 and the bolt-like locking pole 4 is led through 
the elliptic through hole 14 of the adjusting bracket 1 and the housed 
slide board 3. Then the retaining portion 53 of the retaining ratchet 5 is 
engaged with the dentate portion 31 and the ratchet 5 is pivotally mounted 
onto the shaft 51 which is located in the hole 12. Afterwards, the bias 
spring 6 is attached to the shaft 51 and is fixed in between the 
curve-faced block 13 and the retaining ratchet 5 with the hooked end 8 in 
hooking engagement with the retaining ratchet 5, as shown in FIG. 3. 
Next, the cover 2 is engaged with the securing face 11 of the adjusting 
bracket 1 with the shaft 51 passing through the hole 22 and the locking 
pole 4 slidably engaged in through hole 14 secured in place by a screw 9 
extending through the elliptic hole 23 to complete the assembly. 
In practical operation the retaining portion 53 of the retaining ratchet 5 
is retained in the dentate portion 31 first, and when the adjusting 
bracket 1 is pulled upwardly, the retaining ratchet 5 will be pivoted by 
the dents of the dentate portion 31 to press against the bias spring 6, 
permitting the adjusting bracket 1 to be adjusted upwardly, in the 
direction of arrow 4 as shown in FIG. 4. When the adjusting bracket 1 is 
forced downwardly, as shown in FIG. 4, the dents of the dentate portion 31 
will move against the retaining ratchet 5 constantly biased by the bias 
spring 6, resulting in the limiting of the downward movement of the 
adjusting bracket 1. So, the armrest can be only adjusted in the present 
situation. 
As the armrest of the present invention is to be adjusted downwardly, the 
adjusting bracket is first pulled upwardly in the direction of arrow k all 
the way to its top limit, causing the protruded abutment shoulder 32 on 
slide board 3 to bring the bolt-like locking pole 4 on adjusting bracket 1 
to the bottom end of the elliptic through hole 14 with the locking pole 4 
falling into retaining engagement with the curved sliding portion 52 of 
the retaining ratchet 5 as shown in FIG. 6. In such case, the retaining 
ratchet 5 is pivoted against the bias spring 6 by the locking pole 4 in 
such a manner that the retaining portion 53 of the retaining ratchet 5 is 
pivoted out of the linear moving path of the dentate portion 31 of the 
slide board 3, as shown in FIGS. 5, 6. So, the adjusting bracket 1 is free 
to move downwardly when pushed by force. 
As shown in FIG. 7, when the adjusting bracket 1 is pushed all the way to 
its bottom end in, the direction of arrow y, the extended limiting member 
33 secured to the slide board 3 will move along the downwardly pushed 
adjusting bracket 1 and urge against the retained locking pole 4 to set it 
free from the curved sliding portion 52, making the locking pole 4 move to 
the top of the elliptic through hole 14. Accordingly, the retaining 
bracket 5 urged by the bias spring 6 will resume its retaining engagement 
with the dents of the dentate portion 31 of the slide board 3, as shown in 
FIGS. 7, 8. It is apparent that the armrest of the present invention can 
be easily adjusted upwardly or downwardly by simple actuation of the 
adjusting bracket.