U.S. patent application number 09/727829 was filed with the patent office on 2002-05-30 for vehicle drive clutch control.
Invention is credited to Averill, Bryan M., Heravi, Oliver, Karambelas, Randy C., Lines, Peter A..
Application Number | 20020063027 09/727829 |
Document ID | / |
Family ID | 24924245 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020063027 |
Kind Code |
A1 |
Karambelas, Randy C. ; et
al. |
May 30, 2002 |
Vehicle drive clutch control
Abstract
A clutch control for shifting a vehicle drive system as between
automatic four-wheel drive, locked four-wheel drive and two-wheel
drive. An engagement system for engaging drive and driven
components of the drive system may include roller clutch engagement
or pawl clutch engagement. The clutch system is provided with a
coupling mechanism for coupling the engagement member to ground or
to the driven member to thereby achieve automatic four-wheel drive
and locked four-wheel drive, respectively. The engagement member is
decoupled from both ground and the driven member to achieve
two-wheel drive.
Inventors: |
Karambelas, Randy C.;
(Milwaukie, OR) ; Averill, Bryan M.; (Portland,
OR) ; Heravi, Oliver; (Tigard, OR) ; Lines,
Peter A.; (Portland, OR) |
Correspondence
Address: |
Robert L. Harrington
Pacwest Center, Suite 1920
1211 S.W. Fifth Avenue
Portland
OR
97204-3713
US
|
Family ID: |
24924245 |
Appl. No.: |
09/727829 |
Filed: |
November 30, 2000 |
Current U.S.
Class: |
192/35 ; 180/247;
192/84.6; 192/84.7 |
Current CPC
Class: |
B60K 17/35 20130101;
B60K 23/0808 20130101; F16D 41/08 20130101 |
Class at
Publication: |
192/35 ;
192/84.6; 192/84.7; 180/247 |
International
Class: |
B60K 023/08 |
Claims
The invention claimed is:
1. A vehicle having drive clutch control comprising: a clutch
control arrangement positioned in a vehicle's drive line for
controlling a pair of wheels selected from a front pair and a rear
pair of wheels; a drive member and a driven member in said clutch
control arrangement; an engaging member mounted for selectively
engaging the drive member and the driven member and said engaging
member convertible between a first driving mode where the engaging
member does not produce engagement, a second driving mode where the
engaging member produces engagement only when the drive member
overruns the driven member, and a third driving mode where the
engaging member produces engagement when either the drive or driven
member overruns the other; an electrically powered actuator
connected to said engaging member, a vehicle sensing system that
collects data from the vehicle's working components including wheel
speed of the vehicle's wheels, and an analyzer connected to said
vehicle's sensing system and receiving said data for determining a
desired driving mode and for transmitting an electrical signal
indicating the desired driving mode; said actuator connected to
said analyzer and responsive to said electrical signal for
initiating the desired mode of engagement.
2. A vehicle having drive clutch control comprising: a clutch
control arrangement positioned in a vehicle's drive line for
controlling a pair of wheels selected from a front pair and a rear
pair of wheels; a drive member and a driven member in each said
clutch control arrangement; an engaging member mounted for
selectively engaging the drive member and the driven member and
said engaging member convertible between a first driving mode where
the engaging member does not produce engagement, a second driving
mode where the engaging member products engagement only when the
drive member overruns the driven member, and a third driving mode
where the engaging member produces engagement when either the drive
or driven member overruns the other; an electrically powered
actuator connected to said engaging member, a manual switch
connected to the actuator and accessible to an operator of the
vehicle, said switch manually selectively providing electrical
signals to initiate a desired mode of driving.
3. A vehicle as defined in claim 1 wherein the drive member, driven
member and engaging member are cooperatively configured to provide
a roller clutch engagement including rollers and a roller cage
controlling the positioning of the rollers between mated surfaces
of the drive and driven members, a coupler between the actuator and
the roller cage, said coupler responsive to said actuator for
selective coupling of the roller cage to the driven member for
selective coupling of the roller cage to ground and for selective
non-coupling of the roller cage to either the driven member or
ground, and thereby producing selectively the driving modes of
locked four-wheel drive, automatic four-wheel drive and two-wheel
drive, respectively.
4. A vehicle as defined in claim 1 wherein the drive member, driven
member and engaging member are cooperatively configured to provide
pawl clutch engagement including pawls projectable from the drive
member to the driven member in either direction of relative
rotation, a control plate operable to control the projection of the
pawls, and a coupler between the actuator and the control plate,
said coupler responsive to said actuator for selective coupling of
the control plate with the driven member to produce locked
four-wheel drive, coupling of the control plate to ground to
produce automatic four-wheel drive, and non-coupling of the control
plate with either to produce two-wheel drive.
5. A vehicle as defined in claim 1 wherein the actuator comprises
first and second electromagnets and an armature associated with
said electromagnets, said armature coupled to the engaging member;
said first electromagnet when energized producing attraction
between the armature and the driven member to produce locked
four-wheel drive, said second magnet when energized producing
attraction between the armature and ground to produce automatic
four-wheel drive and two-wheel drive produced with the first and
second electromagnets not energized.
6. A vehicle as defined in claim 1 wherein the actuator comprises a
two-stage electromagnet having first and second levels of magnetic
attraction and a two-stage spring member having first and second
levels of spring bias, and an armature coupled to said engaging
member and responsive to the magnetic attraction and the spring
bias to produce the three driving modes as a result of no magnetic
attraction and first and then second levels of magnetic
attraction.
7. A vehicle as defined in claim 1 wherein said actuator comprises
a coupler coupled to the engaging member and movable relative to
the engaging member to couple the engaging member selectively to
the driven member, with ground and non-engagement with either as a
result of movement of the coupler.
Description
FIELD OF THE INVENTION
[0001] This invention relates to vehicles that can be converted
between four-wheel and two-wheel drive and more particularly to the
manner of controlling the different modes of engagement.
BACKGROUND OF THE INVENTION
[0002] It is common to provide vehicles with the capability to
transfer or convert between four-wheel and two-wheel drive. A
vehicle is typically provided with permanent rear wheel drive and
the front wheels are provided with selective drive. The front
wheels may be provided with a type of front wheel drive referred to
as automatic four-wheel drive where the front wheels are driven
only when the rear wheels overdrive the front wheels. They may
instead or additionally be provided with a locked four-wheel drive
where the rear wheels and front wheels are driven together under
all conditions.
[0003] There are benefits and advantages of each mode of operation
(two-wheel drive, automatic four-wheel drive and locked four-wheel
drive). Two-wheel drive mode is the most efficient. The drive
mechanism (propellor shaft, differential gears and axles) for the
front wheels are rendered inactive and that drive mechanism does
not consume power and does not wear when idle. Automatic four-wheel
drive mode is the easiest for the driver. The driver does not have
to forecast when four-wheel drive may be needed, it is not
operational when it is not needed and it engages when needed.
Locked four-wheel drive may be considered the safest and most
reliable. It provides for engine braking of the front wheels and it
always produces driving of all four wheels whether going forward or
backward.
[0004] Numerous situations could be described wherein the driving
conditions favor one form of drive mode over the others. The
present invention is directed to a control feature that provides
selection as between the different modes of drive. The control may
be designed for manual selection and/or it may be designed for
automatic selection of the desired drive mode (referred to
sometimes as smart control).
BRIEF DESCRIPTION OF THE INVENTION
[0005] Switching between two-wheel drive and automatic four-wheel
drive is known and two systems for accomplishing this conversion
are referred to as the pawl clutch system (see U.S. Pat. Nos.
5,927,455 and 5,967,277) and the roller clutch system (see U.S.
Pat. No. 5,195,604). In both of these clutch systems a clutch
mechanism is positioned between a drive and driven member and
controlled by a control member. The control members have limited
rotation relative to the drive member. The control members are
frictionally engaged with "ground" and are accordingly urged to a
trailing position as permitted by said limited relative rotation.
In the trailing position, the clutch mechanism inter-engages drive
and driven members when the drive member attempts to overrun the
driven member and does not produce inter-engagement of the drive
and driven members when the driven member overruns the drive
member. This is the automatic four-wheel drive mode of driving and
functions the same whether driving forward or reverse. That is,
upon reverse driving the trailing position of the control member is
at the opposite end of the permitted relative rotation as between
the control member and drive member and the clutch mechanism
reverses in operation.
[0006] The present invention recognizes that if the control members
become frictionally engaged to the driven member instead of to
ground, the control member will still be urged to the trailing
position of relative rotation when the drive member tries to
overdrive the driven member (the same as in automatic four-wheel
drive mode). However, the control member will also be urged to the
opposite or leading position of relative rotation (as between the
drive member and control member) if the driven member tries to
overrun the drive member. The latter position is the same position
as if the vehicle were driven in reverse and produces
inter-engagement of the drive and driven members. Thus, the drive
and driven members are locked together regardless of which member
attempts to overrun the other which is the locked four-wheel drive
mode.
[0007] It is also a characteristic of both the pawl clutch system
and the roller clutch system that when the control member is
substantially centered between the rearward most position and
forward most position of permitted relative rotation with the drive
member, the clutch mechanism provides no inter-engagement as
between the drive and driven members. (There is an alternate
arrangement of the pawl clutch system but the present invention
utilizes that arrangement wherein the pawls are disengaged in the
centered position.)
[0008] The present invention provides the capability of shifting
the control member between positions of frictional engagement with
ground, frictional engagement with the driven member and no
frictional engagement. A centering mechanism urges centering of the
control member between the rearward and forward most positions of
relative rotation and when there is no frictional urging of the
control member, the drive and driven members are free to rotate
independently, which is the two-wheel drive mode.
[0009] Three different embodiments are disclosed herein for
shifting the control member between the different modes of
operation. The preferred embodiment utilizes a motor-driven lead
screw that shifts a fork. The fork engages the control member and
shifts the control member between a position of engagement with the
driven member, engagement with ground and an intermediate position
of non-engagement with either.
[0010] A second embodiment of the invention uses two
electromagnets. An armature is in frictional engagement with the
control member. The first electromagnet generates attraction of the
armature and thus the control member to the driven member (locked
four-wheel drive). The second electromagnet generates attraction of
the armature to ground (automatic four-wheel drive). With both
electromagnets deactivated, the armature rotates freely and the
control member is urged by a centering spring to its center
position (two-wheel drive).
[0011] A third embodiment uses a two-stage electromagnet and a
return spring acting against an axially movable armature. The
armature is rotatively coupled to the control member and the return
spring urges the control member into frictional engagement with the
driven member (locked four-wheel drive). Activation of the
electromagnet generates a magnetic force that opposes the spring
and draws the armature away from the driven member. The spring and
electromagnet are cooperatively designed to provide one force level
sufficient to draw the armature into frictional engagement with the
coil which is grounded (automatic four-wheel drive). An
intermediate magnetic force level draws the armature away from the
control member which releases the frictional engagement with the
driven member but not into frictional engagement with the coil. The
centering mechanism then centers the control member for two-wheel
drive.
[0012] Whereas the above refers to three different embodiments, it
will be appreciated that each embodiment is applicable to either of
the roller clutch system or the pawl clutch system. Furthermore,
additional systems may be devised and the invention may be
incorporated into further embodiments of the invention as will be
more fully appreciated upon reference to the following detailed
description having reference to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic illustration in plan view of a vehicle
chassis as contemplated for the present invention;
[0014] FIGS. 2 (including 2A and 2B) and 3 are an exploded
isometric view and a sectional assembled view respectively of a
first embodiment of the invention;
[0015] FIGS. 4 and 5 are a sectional assembled view and an exploded
isometric view respectively of a second embodiment of the
invention;
[0016] FIGS. 6 and 7 are sectional assembled view and an exploded
isometric view respectively of a third embodiment of the invention;
and
[0017] FIG. 8 illustrates the automatic control for the mechanisms
of all of the embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 1 illustrates schematically the components of a vehicle
chassis to which the invention applies. The vehicle as shown
includes rear wheels 10 and front wheels 12. An engine 14 is
coupled to a transmission 16 which rotatably drives a propellor
shaft 18. The propellor shaft 18 is coupled to a rear differential
22 from which rear axles 20 are driven for driving rear wheels
10.
[0019] The transmission 16 is coupled to a transfer case 24 for
selectively driving front propellor shaft 26 (as controlled by
shift mechanism 25). Shaft 26 is coupled to the front differential
29 for driving front axles 28 and front wheels 12. The clutch
mechanism, as will now be described, may be incorporated into
various positions in the drive train, but for purposes of this
description it will be assumed to be incorporated into the transfer
case 24 with the output to the front propellor shaft 26 being the
driven member. Input is provided to the drive member from
transmission 16.
[0020] FIGS. 2 (2A and 2B) and 3 illustrate a first and preferred
embodiment of the invention. From the drawings item 30 is the drive
member and item 32 is the driven member. Collar 33 is secured to
the drive member 30 via matching splines 34 on collar 33 with
splines 36 on the drive member 30. Upon assembly as seen in FIG. 3,
a bearing washer 38 accommodates relative rotation as between the
driven member 32 and the collar 33/drive member 30.
[0021] As shown in FIG. 2, three formed seats 40 are provided in
the periphery of the collar 33 for receiving pawls 42 and biasing
springs 44. The springs urge the pawls to project radially
outwardly into formed shoulders 46 provided in the driven member
32. The pawls 42 have an axial projecting portion 48 (see FIG. 3)
that projects into cam slots 50 of control plate 52. Rotation of
the control plate 52 relative to the collar 33/drive member 30
allows selected pawls 42 to project into the shoulders 46 for
engagement between the drive member and driven member. (See Patent
Nos. 5,927,455 and 5,967,277 for further detail and explanation
about this pawl clutch operation.)
[0022] A centering spring 54 is rotatively fixed relative to the
drive member 30/collar 33 through engagement of nibs 55 of the
spring 54 with the walls of gap 57 in rim 59 of collar 33. The nibs
55 of spring 54 project into the relief 74 (established by the
forming of tabs 56) of control plate 52 and thereby urge the
control plate 52 to a centered position whereat the formed seats 40
and thus the pawls 42 are centered relative to slots 50 in the
control plate 52. (A similar centering spring is disclosed in FIGS.
18, 18A and 18B of the '455 patent.) The three tabs 56 of control
plate 52 project into slots 58 of disk 60 so that the control plate
52 and disk 60 are rotatively fixed together.
[0023] A brake drum 64 is rotatively mounted on drive member 30
(via bearing 62 seen in FIG. 3). Adjacent to the disk 60, a
rotatively fixed cage 66 carries brake pads 68 and a garter spring
70 urges the brake pads against the brake drum 64 to urge
non-rotation of the drum 64.
[0024] From FIG. 3, it will be appreciated that movement of control
plate 52 axially into frictional engagement with driven member 32
(at area 53) will urge the control plate 52 to follow the driven
member. As the driven member shifts to a position of overrunning
drive member 30/33, and then shifts to a position of being overrun
by drive member 30/33, the control plate 52 similarly shifts first
to one end of the limited relative rotation permitted between the
control plate and drive member and then to the other end of such
limited rotation. (The limited relative rotation is controlled by
stop 72 on collar 33 being projected into the relief 74 provided by
the formation of tab 56.) Because first one set and then the other
of the pawls 42 are thereby engaged with corresponding shoulder
formations 46, the drive and driven components are locked together
in either direction of relative rotation, i.e., the locked
four-wheel drive mode.
[0025] Now consider that the control plate 52 is axially released
from frictional engagement with the driven member 32 and the disk
60 is shifted into engagement with drum 64. Such engagement is
provided by the circular features 65 on disk 60 being projected
into slots 67 of drum 64 (see FIG. 2B). Drum 64 is frictionally
engaged to ground which urges retarded rotation of disk 60. Disk 60
is rotatively locked to control plate 52 (via tabs 56) and thus the
control plate is rotatively retarded. The control plate maintains a
rearward most position and therefore only permits pawl engagement
when the drive member attempts to overrun the driven member. This
is automatic four-wheel drive.
[0026] By shifting both the control plate 52 and the disk 60 to a
mid-position, i.e., non-engagement with either the driven member or
drum 64, the centering spring 54 centers the control plate and the
drive and driven members are free to rotate independent of one
another. (The two-wheel drive mode.)
[0027] The actuating mechanism for producing the shifting of the
control plate and disk 60 is also shown in FIGS. 2 and 3. A lead
screw 76 is rotatively mounted in cage 78. One end of screw 76 is
attached to a worm wheel 80 having peripheral teeth 82. A worm gear
84 is attached to the shaft of the drive motor 86 and engages the
teeth 82 to rotate the lead screw. A nut 88 is threadably engaged
with threads 90 of the lead screw 76. The nut 88 is prevented from
rotating with the lead screw (a yoke 92 of the nut 88 engages a
guide dowel 94 to allow sliding and prevent rotation of the nut) so
that rotation of the lead screw causes axial movement of the nut. A
fork 96 having ears 98, 100 is slidably mounted on the lead screw.
The ears are positioned at each side of the nut and compression
springs 102, 104 are mounted between the nut and each of the ears
98, 100.
[0028] In operation, the motor 86 receives an electrical signal
that induces rotation of worm wheel 80 which rotates lead screw 76
and forces left or right movement of the nut 88. The corresponding
spring 102, 104 is urged against the corresponding ear 98, 100 to
shift fork 96 to any of the three positions previously described,
i.e., toward the left to produce frictional engagement of the
control plate with the driven member 32 or to the right to force
engagement of the disk 60 with brake drum 64; or to a mid-position
out of engagement with either.
[0029] FIGS. 4 and 5 illustrate a second embodiment of the
invention. Item 106 is the drive member and item 108 is the driven
member. The inner surface 110 of the driven member 108 is a
cylindrical surface which surrounds the periphery 112 of the drive
member 106. The periphery 112 is a polygon including numerous flat
surfaces 114 which intersect to form corners 115. Interposed
between the surface 110 and periphery 112 are rollers 116. The
rollers 116 are contained within a cage 118 (which corresponds to
the control plate of the first embodiment.) The rollers are sized
to be greater than the radial distance between the surface 110 and
the periphery 112 (at the center of the flat surfaces 114) and
greater than the smallest radial distance between the surface and
the periphery (at the corners or junctures of the flat surfaces).
Thus, the cage and rollers have limited rotation relative to the
drive member (they are trapped between the corners). At a center
position on the flat surfaces, the rollers permit free rotation of
the driven member relative to the drive member. As the rollers move
toward the corners in either direction, they become wedged between
the drive and driven members and interlock the drive and driven
members. (See U.S. Pat. No. 5,195,604 for a more detailed
explanation of the roller clutch operation.)
[0030] A centering spring 120 is rotatively secured to the drive
member 106 and is engaged by the roller cage 118 (nibs 121 fit
notch 119). The nibs can be biased apart for resisted relative
movement and urge the cage to a center position relative to the
drive member 106, i.e., with the rollers 116 centered on the flat
surfaces 114.
[0031] The roller cage 118 includes a splined hub portion 122 on
which brake shoes 124 are engaged. An expansion spring 126 urges
the shoes 124 radially outwardly against a shaped armature 128. The
armature is shaped to have an upper cup shape and a lower stem as
seen in the upper half of FIG. 4. Positioned in close adjacency
within the cup portion is a first fixed electromagnetic coil 130
and positioned in close adjacency to the stem portion of the
armature 128 is a second fixed electromagnetic coil 132. The brake
shoes 124 are urged radially outwardly against the bottom leg 134
of the cup shaped portion of the armature by spring 126.
[0032] As illustrated by directional arrows, a magnetic force mf1
is generated when electromagnet 130 is activated and magnetic force
mf2 is generated when electromagnet 132 is actuated.
[0033] In operation, with both electromagnets de-activated, the
armature 128 is allowed to rotate freely. The centering spring 120,
121 urges the cage to its centered position (the rollers centered
on flat surfaces 114) and there is no engagement between the drive
and driven members. This is the two-wheel drive mode.
[0034] By activation only of electromagnet 130, the magnetic field
mf1 produces a magnetic attraction as between the armature 128 and
the driven member 108. Regardless of the relative rotation as
between the drive and driven members (106, 108) the roller cage and
thus the rollers are urged toward either of the rearward or forward
corners 115 and the drive and driven members become locked, i.e.,
the drive and driven members are forced to rotate substantially in
unison. This is the locked four-wheel drive position.
[0035] By activation only of electromagnet 132, the magnetic field
mf2 produces a magnetic attraction between the armature 128 and the
electromagnetic coil 132 which is grounded. The armature thus
resists rotation to urge retardation of the roller cage (via the
brake shoes 124) which accordingly urges the rollers to a trailing
position. Anytime the drive member tries to overrun the driven
member, the rollers lock up and the drive member and driven member
rotate together. When the driven member attempts to overrun the
drive member, the rollers are urged to a center position and the
driven member is free to rotate faster than the drive member. This
is the automatic four-wheel drive mode.
[0036] A third embodiment is illustrated in FIGS. 6 and 7. This
embodiment is similar to the first embodiment with respect to the
manner of engagement and many of the components are similar both in
appearance and operation. Accordingly, similar reference numbers
will be used and the reader is referred to the explanation and
description of the first embodiment.
[0037] The control plate of this third embodiment is somewhat
different and is identified by reference 52'. The cam slots which
function to control the projection of the pawls 42 are similar to
that of the first embodiment and are identified as item 50. Notches
136 are provided on the periphery of the control plate 52'. A disk
shaped armature 138 is mounted adjacent control plate 52' and
axially directed tabs 140 from the armature 138 are engaged with
the notches 136 of the control plate. The armature can move axially
(as can control plate 52' to a limited extent) and can also move
axially relative to the control plate as will be noted from the
split illustration of FIG. 6. The armature and the control plate
nevertheless remain rotatively locked together.
[0038] A two-stage (or dual spring arrangement) 142 urges movement
of the armature 138 toward the control plate 52'. Bosses 144 are
provided on the armature 138 (but could be on the control plate)
that abuts the control plate and urges the control plate into
abutment with rim 146 of the driven member 32. This places the
control plate in frictional engagement with the driven member and
produces the locked four-wheel drive mode.
[0039] An electromagnet 148 is a two-stage magnet that has both a
strong and weak magnetic attractions. In the strong attraction
setting, the electromagnet draws the armature with sufficient force
to overcome the spring 142 and into engagement with the magnet as
seen in the bottom half of FIG. 6. The magnet is fixed and thus the
armature and control plate are urged to ground. This produces the
automatic four-wheel drive mode.
[0040] With the electromagnet 148 set at the low setting, the
magnetic force is sufficient to overcome the weaker components of
the two-stage spring to withdraw the armature away from the control
plate to separate from the drive member. That magnetic force will
not overcome the stronger spring action which prevents the armature
from engaging the magnet. The centering spring 54 centers the
control plate and the vehicle is placed in two-wheel drive.
[0041] Actuation of the Different Driving Modes
[0042] FIG. 8 schematically illustrates the manner by which the
different driving modes are selected. First, it will be appreciated
that each of the embodiments enable selection as between two-wheel,
locked four-wheel and automatic four-wheel drive modes via
electronic signals. Providing an electronic signal, e.g., from the
vehicle's battery or alternator, is well known as are switches that
select among different electrical paths. A manual select switch can
be made available to a driver of the vehicle and he need only
position the switch as between the three selections to obtain the
desired drive mode.
[0043] This same selection process can be produced automatically
and the combination as between manual and automatic control of the
selection can vary. For example, the setting may be made to permit
only manual operation or only automatic operation or even manual
operation which can be ovc operation. In any position of abutment
with the control plate to thereby allow the event, automatic
operation is at least an option.
[0044] Automatic operation is enabled at least in part by the
existing sensors and computer capability of the vehicle. All modern
vehicles contemplated herein are equipped with the capability and
do monitor innumerable working components of the vehicle, e.g.,
engine speed and acceleration, brake application, speed and
acceleration/deceleration of each wheel, etc. This capability is
represented in FIG. 8 by the block 150 labeled ECU. An analyzer
component 151 is designed to monitor input from selected sensors
and to make comparisons. For example, it will compare the velocity
and acceleration of the front wheels vs. the rear wheels. It will
note the application of the brakes and the rate of braking, also
comparing this information as between the rear and front wheels.
Based on engine power load at vehicle speeds, there may be a
determination whether the vehicle is going uphill or downhill,
whether the vehicle is turning, going forward or in reverse. Any
and all of these factors may be scrutinized and result in the
determination that under the conditions then existing, one or the
other of two-wheel drive, locked four-wheel drive or automatic
four-wheel drive is desirable. As indicated by lines 152a, 152b and
152c, one of the drive modes is engaged as a result of this
analysis.
[0045] The invention is considered to have wide spread application
for vehicles and there are numerous possible and/or probable
variations that can be made without departing from the intended
scope of the invention. Accordingly, the invention is to be
determined based on the definition of the claims appended hereto
and it is to be noted that unless the term "means for" is used in
the claims, it is intended that the claims are not to be
interpreted by .paragraph.6 of 35 USC .sctn.112.
* * * * *