Four-way power lumbar system

A four-way power lumbar support system which provides for both an in-out directional adjustment and an up-down directional adjustment including a pair of directional one-way locking clutches that slip in one direction and lock in another direction, a single motor, and a single gearbox assembly. The motor output drives the two directional one-way locking clutches setup to slip and lock in opposite directions of rotation causing one to engage for clockwise rotation of the motor and the other to engage for counterclockwise rotation of the motor.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention generally relates to a four-way power lumbar support 
system. More particularly, the present invention relates to a four-way 
power lumbar support system which provides outputs for in-out directional 
adjustments and up-down directional adjustments by using a single motor 
and a single gearbox assembly. 
2. Discussion 
A conventional power lumbar support system uses a motor and gearbox 
assembly commonly referred to as an actuator for each mode, adjustment or 
plane of operation. Thus, a two-way power lumbar support system would 
provide an arching directional adjustment of a flexible, resilient support 
element in an in-out direction and require a single actuator. A four-way 
power lumbar support system would provide an arching directional 
adjustment of a flexible, resilient support element plus a level 
directional adjustment, in an up-down direction, which would require two 
separate actuators, one for each adjustment direction. Two such actuators 
promotes complication, increases overall size and weight, and promotes 
duplication of gearbox components. The types of devices as described in 
the current four-way power lumbar support systems also include complicated 
switches which provide for two-directional operation. Such a switch can be 
used to allow the motor to rotate in one direction thus causing adjustment 
in one direction. A second direction reverses the motor thereby causing 
and resulting in a second adjustment direction. 
Accordingly, the need exists to provide an improved, cost-effective, light 
weight and efficient four-way power lumbar support system. The current 
invention creates such a four-way power lumbar support system and offers 
major improvements over previous systems such as providing a 50% savings 
on motors and a significant reduction in gearbox component duplication. 
SUMMARY OF THE INVENTION 
The present invention is a substantial improvement over the current 
four-way power lumbar support systems because it provides a lumbar support 
system that is light weight, flatter in size, has fewer components and is 
less, costly. 
Thus, it is a purpose of the present invention to overcome the 
disadvantages of the current four-way power lumbar support system art and 
thereby provide a relatively light weight, flatter in size, cost efficient 
four-way power lumbar support system. 
It is a principal object of the present invention to provide a four-way 
power lumbar support system which has reduced overall size and weight, 
fewer components, reduction of duplicative gearbox components and is cost 
efficient. 
A related object of the present invention is to provide a four-way power 
lumbar support system which advances and easily accomplishes the comfort 
features of massage and micro-adjustment. 
It is another object of the present invention to provide a four-way power 
lumbar support system which includes a pair of one-way clutches that slip 
in one direction and lock in another direction resulting in two different 
outputs, one that engages for clockwise rotation of the motor and the 
other that engages for counter-clockwise rotation of the motor. 
A related object of the present invention is to provide a four-way power 
lumbar support system which provides for continuous cyclical adjustment of 
each directional adjustment. 
It is another object of the present invention to provide a four-way power 
lumbar support system which provides for an increase in directional 
adjustment limitations through the use of extension arms. 
In one form, the present invention provides the art with a four-way power 
lumbar support system including a flexible support element, an operating 
device and a gearbox assembly. The gearbox assembly includes a pair of 
one-way clutches and a pair of Bowden cable arrangements such that the 
operating device provides for adjustments of the flexible support element. 
Additional benefits, along with other advantages and objects of the present 
invention will become apparent to those skilled in the art from a reading 
of the subsequent detailed description, appended claims and accompanying 
drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, there is depicted a four-way power lumbar 
support system embodying the concepts of the present invention. The 
four-way power lumbar support system of the present invention is generally 
identified in the drawings with reference numeral 10 and is shown through 
the drawings adapted to cooperate with a specific back rest 12 of a seat. 
However, the teachings of the present invention are more broadly 
applicable to back rests for a large range of applications. 
Prior to addressing the construction and operation of the four-way power 
lumbar support system 10 of the present invention, a brief understanding 
of the exemplary back rest 12 shown in FIG. 1 is warranted. The 
environmental view of FIG. 1 illustrates the four-way power lumbar support 
system 10 operatively installed in the back rest 12. The back rest 12 
illustrated is otherwise of conventional construction and shown to 
generally include a frame 14 in which between two transverse struts 16 and 
18, and a guide 20 are fitted. The guide 20 includes two rods 22 and 24 
which are parallel to one another. A support element 26 is operably 
connected to parallel rods 22 and 24 so as to be capable of moving up and 
down the guide 20. The support element 26 may be any general support 
element, made of any general material including plastic, metal or any 
combination thereof, in a plurality of parts or in one piece having an 
upper portion 28 for supporting the lumbar vertebrae and a lower portion 
30 for supporting the pelvis and the pelvic vertebrae. 
The four-way power lumbar support system 10 is capable of adjusting for 
arching, that is, in the in-out direction, as well as for level 
adjustment, that is, in the up-down direction. These adjustments are 
accomplished through the use of Bowden cable arrangements 32 and 34. The 
Bowden cable arrangement 32 is used for arching adjustments, that is, in 
the in-out direction, while the Bowden cable arrangement 34 is used for 
level adjustment, that is, in the up-down direction. The Bowden cable 
arrangements 32 and 34 include a sheath 36 and a sheathed cable 38. The 
sheath 36 of the Bowden cable arrangements 32 and 34 is fixed at one end 
to the support element 26 and at the other end to a gearbox assembly 40. 
The sheathed cable 38 of the Bowden cable arrangements 32 and 34 extends 
from the sheath 36 and is fixed at one end to the support element 26 and 
at the other end to a gear located in the gearbox assembly 40. 
As will become apparent below, the four-way power lumbar support system 10 
is operative to drive both in-out directional adjustments (arching) and 
up-down directional adjustments (level) through the use of a single motor 
and gearbox assembly which reduces overall size and weight, and eliminates 
one complete motor and some duplication of gearbox components. 
With continued reference to FIG. 2, FIG. 3 and FIG. 4, the four-way power 
lumbar support system 10 of the preferred embodiment of the present 
invention will now be further discussed. As shown most clearly in the 
enlarged front view of FIG. 2, the four-way power lumbar support system 10 
includes a gearbox assembly 40, a motor 42 and a housing 43. The motor 42 
includes a drive shaft 44 on which a worm gear 46 is mounted. The worm 
gear 46 mounted to the drive shaft 44 projects into the gearbox assembly 
40 and the housing 43. The worm gear 46 is in tooth engagement with 
directional one-way locking clutches 48 and 50. 
The directional one-way locking clutch 48 includes an outer ring of gear 
teeth 52 and an inner ring 53. The outer ring of gear teeth 52 is 
rotatably attached to the inner ring 53 of the directional one-way locking 
clutch 48 by a key 54 or any other suitable attachment means such that the 
outer ring of gear teeth 52 continuously rotates as the worm gear 46 is 
driven by the motor 42. Similarly, the directional one-way locking clutch 
50 includes an outer ring of gear teeth 56 and an inner ring 57. The outer 
ring of gear teeth 56 is rotatably attached to the inner ring 57 of the 
directional one-way locking clutch 50 by at key 58 or any other suitable 
attachment means such that the outer ring of gear teeth 56 continuously 
rotates as the worm gear 46 is driven by the motor 42. The inner rings 53 
and 57 of the directional one-way locking clutches 48 and 50, respectively 
are designed to slip in one direction and lock in the other direction. The 
directional one-way locking clutch 48 is a mirror image of the directional 
one-way locking clutch 50. That is, the inner ring 53 of the directional 
one-way locking clutch 48 locks during clockwise rotation of the motor 42 
and slips or engages for counter-clockwise rotation of the motor 42. As 
shown most clearly in the enlarged cross-sectional view of FIG. 4, the 
inner ring 53 of the directional one-way locking clutch 48 is illustrated 
in its fully locked position with bearings 60 running up against and 
abutting walls 62, thereby preventing any further rotation of the inner 
ring 53 in the clockwise direction. On the other hand, the inner ring 57 
of the directional one-way locking clutch 50 locks during 
counter-clockwise rotation of the motor 42 and slips or engages for 
clockwise rotation of the motor 42 As shown most clearly in the enlarged 
cross-sectional view of FIG. 3, the directional one-way locking clutch 50 
is illustrated in its fully locked position with bearings 60 running up 
against and abutting walls 62, thereby preventing any further rotation of 
the inner ring 57 in the counter-clockwise direction. The directional 
one-way locking clutches 48 and 50 can be integrated to a great extent 
into the gear components to minimize added expense and complexity. It 
should be noted that anyone of a variety of types of directional one-way 
locking clutches can be used. 
Thus, the direction of rotation of the motor 42 determines whether the 
up-down or the in-out directional adjustments are performed. The 
directional one-way locking clutch 48 mechanically engages a worm gear 64. 
The worm gear 64 is in tooth engagement with a gear wheel 66. Attached to 
the gear wheel 66 is the sheathed cable 38 of the Bowden cable arrangement 
34 such that when the gear wheel 66 rotates, the sheathed cable 38 
provides for up-down directional adjustment. The amount of travel of the 
sheathed cable 38 of the Bowden cable arrangement 34 and thereby the 
amount of up-down directional adjustment provided is controlled by the 
size of the gear wheel 66. For example, during its cycle of rotation, as 
the gear wheel 66 rotates 180.degree., the support element 26 may go 
through its entire range of up directional adjustments. Thereafter, as the 
gear wheel 66 continues to rotate the remaining 180.degree., the support 
element 26 returns and goes through its entire range of down directional 
adjustments. Similarly, the directional one-way locking clutch 50 
mechanically engages a worm gear 68. The worm gear 68 is in tooth 
engagement with a gear wheel 70. Attached to the gear wheel 70 is the 
sheathed cable 38 of the Bowden cable arrangement 32 such that when the 
gear wheel 70 rotates, the sheathed cable 38 provides for in-out 
directional adjustment. The amount of travel of the sheathed cable 38 of 
the Bowden cable arrangement 32 and thereby the amount of in-out 
directional adjustment provided is controlled by the size of the gear 
wheel 70. For example, during its cycle of rotation, as the gear wheel 70 
rotates 180.degree., the support element 26 may go through its entire 
range of in directional adjustments. Thereafter, as the gear wheel 70 
continues to rotate the remaining 180.degree., the support element 26 
returns and goes through its entire range of out directional adjustments. 
In the preferred embodiment, the four-way power lumbar support system 10 
includes a single motor 42, the direction of rotation of which determines 
whether an up-down or an in-out directional adjustment is performed. The 
motor 42 drives the drive shaft 44 which causes the worm gear 46 to 
rotate. During this rotation of the worm gear 46, the worm gear 46, in 
tooth engagement with the outer ring of gear teeth 52 of the directional 
one-way locking clutch 48 and the outer ring of gear teeth 56 of the 
directional one-way locking clutch 50, causes the outer rings of gear 
teeth 52 and 56 to rotate continuously. If in-out directional adjustments 
are desired, the directional one-way locking clutch 50, which is 
mechanically engaged with the worm gear 68 and engages for clockwise 
rotation of the motor 42, engages, driving the worm gear 68 which in turn 
drives the gear wheel 70 such that the sheathed cable 38 of the Bowden 
cable arrangement 32 provides for in-out directional movement. 
Contemporaneously, as shown in FIG. 4, the directional one-way locking 
clutch 48 is in its fully locked position. 
Similarly, if up-down directional adjustments are desired, the directional 
one-way locking clutch 48, which is mechanically engaged with the worm 
gear 64 and engages for counter-clockwise rotation of the motor 42, 
engages, driving the worm gear 64 which in turn drives the gear wheel 66 
such that the sheathed cable 38 of the Bowden cable arrangement 34 
provides for up-down directional movement. Contemporaneously, as shown in 
FIG. 3, the directional one-way locking clutch 50 is in its fully locked 
position. 
In a second embodiment of the present invention, the amount of up-down and 
in-out directional adjustment is increased. Referring now to FIG. 5 and 
FIG. 6, a second embodiment of the four-way power lumbar support system of 
the present invention is generally identified with reference numeral 100. 
As with the four-way power lumbar support system 10, the right and left 
sides of the gearbox assembly 40 are mirror images of each other. Thus, 
only the in-out directional adjustments are illustrated in FIG. 5 and FIG. 
6. Moreover, like reference numbers from the four-way power lumbar support 
10 will be used to describe similar components. 
The four-way power lumbar support system 100 includes a spacer 102, a 
housing 104 having a slot 106 formed therein, a post 108 and a linkage arm 
110. The post 108 is attached by any suitable attachment means to the gear 
wheel 70. Alternatively, the linkage arm 110 could be set in an arcuate 
slot in the sidewall of the housing 104 and attach between the gear wheel 
70 and the Bowden cable arrangement 32. The linkage arm 110 is attached by 
any suitable attachment means to the post 108. The sheathed cable 38 of 
the Bowden cable arrangement 32 is rotatably attached to the linkage arm 
110. Thus, the amount of in-out directional adjustment provided is 
increased on a magnitude of the length of the linkage arm 110. 
A further alternative would include a direct linkage between either the 
gear (or a gear with a linkage arm) and the lumbar support. This direct 
linkage could be used on either one or both gears, and control either the 
up-down and/or the in-out directional features of the lumbar support. 
In the present invention, continuous cyclical adjustment of each direction 
is required because reversing the motor 42 does not reverse the adjustment 
direction, but rather switches motor output to the other adjustment mode. 
That is, if the switch is activated for a particular directional 
adjustment, the four-way power lumbar support system 10 would cycle 
repeatedly in that adjustment mode until the switch is released. Switch 
simplification is thereby possible since two directional operation is no 
longer needed. Additionally, advanced comfort features of massage and 
micro-adjustment can easily be accommodated with the four-way power lumbar 
support system 10, and in some respects are simplified because there is no 
longer a need to reverse direction. 
Moreover, the directional one-way locking clutches 48 and 50 may be located 
at any level of gear reduction away from the motor 42 to optimize torque 
loading vs. speed and generated noise. Operating the directional one-way 
locking clutches 48 and 50 close to the speed of the motor 42 would 
minimize torque requirements but result in high speed running that could 
be noisy and accelerate wear. Operating the directional one-way locking 
clutches 48 and 50 at the highest gear reduction end of the gear train 
would produce slow quiet operation, but require a larger size to carry the 
higher forces. 
The same principles associated with the four-way power lumbar support 
system 10 are also applicable to a manually operated lumbar support 
system. Moreover, the selective routing of the motor output based on motor 
rotation direction can be applied to any motorized application where two 
different and independent adjustments are required, and continuous cycling 
adjustment of the mechanisms is acceptable. 
While the above detailed description describes the preferred embodiment of 
the present invention, it should be understood that the present invention 
is susceptible to modification, variation and alteration without deviating 
from the scope and fair meaning of the subjoined claims.