U.S. patent application number 09/871188 was filed with the patent office on 2001-12-06 for alarm mechanism.
Invention is credited to Spencer, Joseph C..
Application Number | 20010048362 09/871188 |
Document ID | / |
Family ID | 22773545 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010048362 |
Kind Code |
A1 |
Spencer, Joseph C. |
December 6, 2001 |
Alarm mechanism
Abstract
An alarm assembly is provided alerting the operator through one
of a visual, audible, or tactile signal, the occurrence of a
specified event. The alarm assembly includes a locking mechanism
coupled to a substrate which has a natural frequency. The locking
mechanism is maintained in a condition which inhibits the natural
frequency of the substrate unless commanded to do so by an
electronic circuit which includes sensors for monitoring one or
more specific criterion. The locking mechanism is preferably a
non-Newtonian flow fluid locking mechanism which uses a
magneto-rheological fluid to dynamically adjust the locking
strength of the locking mechanism as well as the natural frequency
of the substrate based upon user inputs and dynamic events. The
alarm assembly can be dynamically "tuned" in and out of the natural
frequency of the substrate so the substrate vibrates, produces an
audible noise, or generates a current upon the occurrence of a
predetermined event. Sensors mounted on the substrate provide
feedback via a logic system or computer to alter the stiffness of
the locking system and increase or decrease the vibration to obtain
or avoid the natural frequency.
Inventors: |
Spencer, Joseph C.;
(Coldwater, MI) |
Correspondence
Address: |
MILLER JOHNSON SNELL COMMISKEY
800 CALDER PLAZA BUILDING
250 MONROE AVE N W
GRAND RAPIDS
MI
495032250
|
Family ID: |
22773545 |
Appl. No.: |
09/871188 |
Filed: |
May 31, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60208181 |
May 31, 2000 |
|
|
|
Current U.S.
Class: |
340/425.5 ;
340/438; 340/683 |
Current CPC
Class: |
B60R 21/01 20130101;
B62D 1/184 20130101; B60R 25/02105 20130101; B62D 15/029
20130101 |
Class at
Publication: |
340/425.5 ;
340/438; 340/683 |
International
Class: |
B60Q 001/00 |
Claims
I claim as my invention:
1. An apparatus for alerting an operator to a specific condition,
comprising: a magneto-rheologic assembly; a substrate coupled to
said magneto-rheologic assembly; at least one sensor at a first
location for detecting an occurrence of the specific condition and
producing an output signal; and a circuit interconnected to said
sensor and to said magneto-rheologic assembly for changing a
natural frequency of said magneto-rheologic assembly and said
substrate in response to said output signal received from said at
least one sensor, said change in said natural frequency generating
at least one of a vibration and an audible signal in said substrate
for sensing by the operator to alert the operator to the specific
condition.
2. The apparatus as defined in claim 1, wherein said substrate is
coupled to a control.
3. The apparatus as defined in claim 1, wherein said
magneto-rheologic assembly is coupled to an resonating substrate
which produces an audible signal when at said natural
frequency.
4. The apparatus as defined in claim 1, wherein said
magneto-rheologic assembly is attached to a portion of a seat for
the operator through which said signal is sensed by said
operator.
5. The apparatus as defined in claim 1, wherein said at least one
sensor monitors a relative distance between two points.
6. The apparatus as defined in claim 1, wherein said at least one
sensor monitors operator awareness.
7. The apparatus as defined in claim 1, wherein said circuit
includes one of a controller, a programmable logic circuit, a
computer, and a dedicated hard-wired circuit.
8. The apparatus as defined in claim 1, further including apparatus
attached to said substrate for providing dynamic feedback to said
circuit.
9. The apparatus as defined in claim 2, wherein said control
includes at least one of a steering wheel, a control stick, an
accelerator, and a shifter assembly.
10. A dynamically controlled alarm assembly, comprising: a
substrate having a natural frequency; a magneto-rheological device
attached to said substrate and controlling an occurrence of said
natural frequency in said substrate; a first sensor for monitoring
a desired characteristic; a second sensor at a location different
from that of said first sensor and for monitoring said natural
frequency of said substrate; and a circuit interconnected to said
first sensor, said second sensor, and said magneto-rheologic device
for controlling said natural frequency of said substrate by
changing a characteristic of said magneto-rheologic device in
response to feedback from said first and second sensors.
11. The dynamically controlled alarm assembly as defined in claim
10, wherein said substrate produces an audible signal when at said
natural frequency.
12. The dynamically controlled alarm assembly as defined in claim
10, wherein said substrate produces a tactile signal when at said
natural frequency.
13. The dynamically controlled alarm assembly as defined in claim
10, wherein said substrate produces a visual signal when at said
natural frequency.
14. The dynamically controlled alarm assembly as defined in claim
10, wherein said natural frequency of said substrate is
tunable.
15. The dynamically controlled alarm assembly as defined in claim
10, wherein said substrate includes at least one of a control, a
seat, and a display.
16. The dynamically controlled alarm assembly as defined in claim
10, wherein said first sensor detects a relative change in
predetermined parameters.
17. The dynamically controlled alarm assembly as defined in claim
10, wherein said circuit includes at least one of a controller, a
computer, and a dedicated hard-wired circuit.
18. The dynamically controlled alarm assembly as defined in claim
10, wherein said magneto-rheological assembly include a
non-Newtonian flow fluid locking assembly.
19. An alarm system, comprising: a non-Newtonian flow fluid locking
assembly; a substrate having a natural frequency, coupled to said
non-Newtonian flow fluid locking assembly, said substrate producing
at least one of an audible, tactile, and visual signal when at said
natural frequency; at least a first sensor mounted to said
substrate to monitor said natural frequency of said substrate; at
least a second sensor spaced from said first sensor for detecting
the occurrence of a predetermined condition; and a circuit assembly
operably interconnected to said first and second sensors and to
said non-Newtonian flow fluid locking assembly for monitoring said
first and second sensors and changing a condition of said
non-Newtonian flow fluid locking assembly in response thereto such
that upon the occurrence of said predetermined condition, said
non-Newtonian flow fluid locking system permits said substrate to
achieve said natural frequency and produce said at least one of
said audible, tactile and visual signal.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent
application serial No. 60/208,181 filed May 31, 2000, the
specification of which is incorporated herein by reference
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to alarm systems and
particularly to a mechanism for actively alerting an operator of
the occurrence of a specific condition requiring the attention of
the operator.
[0004] 2. Discussion of the Related Art
[0005] Substantially all mechanical devices, and in particular
vehicles, have structures which have a "natural frequency." The
"natural frequency" of a component is the frequency at which a
system oscillates in the absence of external forces; or, for a
system with more than one degree of freedom, the frequency of one
of the normal modes of vibration. Particular care is given during
the designing of these components to avoid the "natural frequency."
The goal in most cases is to remove unwanted vibration to provide
smooth and comfortable operation of the machine.
[0006] From an automobile manufacturer's viewpoint, the natural
frequency of a component or assembly should be higher than a
particular threshold, else the operator of the vehicle may detect
some undesirable vibration, rattle, or "singing" during operation
which is distracting, annoying, or disconcerting. Always, when an
automobile manufacturer provides specifications to outside or third
party vendors/suppliers, the natural frequency floor for the
desired component/assembly is usually set out and is to be avoided.
To the best of the inventor's knowledge, never has the natural
frequency of a component been used to alert the operator of a
condition.
SUMMARY OF THE INVENTION
[0007] The instant invention is an apparatus for interconnecting
two objects together and permits the relative position of the two
objects to be adjusted while the device is in a first state, and
fixes the relative position of the two objects while the device is
in a second state. The state of the device can be dynamically
driven, and in particular, "tuned" to either avoid, or induce, the
natural frequency of the coupled structures.
[0008] The apparatus embodying the invention includes a housing
having at least one movable piston inside. Also inside the housing
is a non-Newtonian flow fluid which passes through at least one
passage within the housing. Adjacent the passage, or in close
proximity thereto, is a device for selectively generating or
neutralizing a magnetic field in and around the passage. The fluid
within the housing flows through the passage when the magnetic
field is weak or absent permitting the piston to move. When the
magnetic field surrounding the passage reaches a predetermined
strength, the fluid undergoes a change and ceases to flow, locking
the relative position of the piston within the housing. If the
strength of the field is increased, the effect of the field extends
beyond that of the passage, and renders the device to be more
rigid.
[0009] In one form of the invention, the invention is used to
adjustably fix the relative position of the two interconnected
components. The novel assembly includes an upper housing assembly
coupled to a lower housing assembly in a manner to permit at least
one of the upper and lower housing assemblies to articulate and
telescope relative to the lower housing assembly. At least one
non-Newtonian flow fluid-locking mechanism interconnects the upper
housing assembly to the lower housing assembly for selectively
fixing their relative positions. It is contemplated the apparatus
includes a device for generating a magnetic field around at least a
portion of the non-Newtonian flow fluid-locking mechanism for
selectively activating and deactivating the fluid-locking
mechanism. An electronic circuit and sensors are interconnected to
the non-Newtonian flow fluid-locking device to dynamically adjust
the strength of the magnetic field, thereby adjusting the rigidity
of the locking mechanism. In the event the sensors detect the
occurrence of a predetermined event, the strength of the magnetic
field in the locking mechanism is changed to match the natural
frequency of the component which produces one of an audible,
tactile or visible signal to the operator. For example, in the
event a sensor detects an object adjacent the left side of the
vehicle, the circuit may be programmed to increase the magnetic
field in the locking mechanism which controls the turn rate of the
steering wheel, essentially providing tactile feed back to the
operator which makes it more difficult to turn left and into the
obstacle.
[0010] In yet another form of the invention, it is contemplated
that the invention may be used to lock the rotation of the steering
column, and act as a vehicle anti-theft system in the event the
vehicle is broken into. The system would not deactivate until the
key was inserted or some other system releases the device.
Additionally, it is contemplated that the invention may be used to
fix the relative position of seats, control pedals, and other
objects within a vehicle, or match the natural frequency of those
components such that they vibrate and provide a physical stimulus
to the operator.
[0011] In still another form of the invention, an adjustable
steering column is provided which is capable of tilting,
telescoping, or both to the operators desired position. The locking
system provided to fix the desired position of the steering column
is dynamically adjusted or "tunable" in and out of the natural
frequency of the steering column so the steering column vibrates
upon the occurrence of a predetermined event. Sensors are mounted
on the steering column to provide feedback via a logic system or
computer to alter the stiffness of the locking system and increase
or decrease the vibration of the column. For example, sensors could
monitor the operator's eyes and determine when he/she has fallen
asleep. If a condition is met, the locking mechanism is adjusted to
permit the column to vibrate, and wake-up the operator. Once the
condition is no longer satisfied, the system is tuned so the
vibration stops and returns to normal operation. Similar systems
could be used with seats, shift levers, control pedals, and the
like.
[0012] These and other objects, advantages, purposes, and features
of the invention will become more apparent from a study of the
following description taken in conjunction with the drawing figures
described below.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0013] FIG. 1 is a schematic diagram of one environment of
application of the instant invention;
[0014] FIG. 2 is an enlarged elevation view of the invention shown
in FIG. 1;
[0015] FIG. 3 is a bottom plan view of the invention shown in FIG.
2;
[0016] FIG. 4 is a schematic section view of one embodiment of the
invention shown in FIGS. 2 and 3;
[0017] FIG. 5 is a schematic section view of an alternate
embodiment of the invention shown in FIGS. 2 and 3;
[0018] FIG. 6 is a schematic section view of an embodiment of the
invention in a telescoping assembly;
[0019] FIG. 7 is a schematic view of another application of the
instant invention;
[0020] FIG. 8 is a schematic diagram illustrating a circuit used in
combination with the instant invention to adjust the
characteristics of the invention in response to specific input;
[0021] FIG. 9 is an oblique view of a tilting and telescoping
steering column employing other embodiments of the instant
invention;
[0022] FIG. 10 is an elevation section view of the invention shown
in FIG. 9;
[0023] FIG. 11 is an oblique view of an embodiment of the instant
invention used for translation of components;
[0024] FIG. 12 is a longitudinal section view of the invention
shown in FIG. 11; and
[0025] FIG. 13 is a fragmentary section view of the invention shown
in FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] For purposes of the following description, the terms
"upper," "lower," "right," "left," "rear," "front," "vertical,"
"horizontal" and derivatives thereof shall relate to the invention
as oriented in FIG. 2. However, it is to be understood that the
invention may assume various alternative orientations except where
expressly specified to the contrary. It is also to be understood
that the specific devices and processes illustrated in the attached
drawings, and described in the following specification, are simply
exemplary embodiments of the inventive concepts defined in the
specification and any appended claims. Specific dimensions and
other physical characteristics relating to the embodiments
disclosed herein are not to be considered as limiting, unless the
claims expressly state otherwise.
[0027] Although the instant invention has application to
substantially any situation where it is desirable to prompt an
operator to the occurrence of an event, the following description
is made with specific reference to applications in vehicles, and
more to a steering column where it is common to provide tilt and/or
telescoping movement of one component (the steering wheel) relative
to another (the steering column).
[0028] Referring to drawing FIGS. 1 through 3, a steering column
assembly 10 is shown mounted in a vehicle 12 such as a truck,
wherein a steering wheel assembly 14 is provided at one end, and
the opposite end is interconnected to a steering gear box 16 for
steering the front wheels of the vehicle 12. The upper portion of
the steering column assembly 10 (FIG. 2) includes a lower housing
assembly 20 interconnected to the upper housing assembly 22 in a
manner to permit articulation or tilting of the upper housing
assembly 22 relative to the lower housing assembly 20, translation
or telescoping motion of the upper housing assembly 22 relative to
the lower housing assembly 20, or both. In the embodiment shown,
upper housing assembly 22 is pivotally coupled at its lower end 24
by pins 26 to arms 28 of a yoke 30 attached to the upper end 32 of
the lower housing assembly 20. The pivot axis defined by pins 26 is
preferably substantially horizontal to provide for a limited arc of
rotation in a vertical plane.
[0029] The upper and lower housing assemblies 22 and 20,
respectively, of the steering column assembly 10 enclose a series
of interconnected rotatable shafts (not shown) connected at one end
to the steering wheel assembly 14 and at an opposite end to a
steering gear box 16. A universal joint or similar coupling
interconnects the shafts to permit tilt movement of the upper
housing assembly 22 relative to lower housing assembly 20. A
telescoping shaft may be attached to the upper shaft to permit
longitudinal adjustment of the steering column assembly 10.
[0030] Lower housing assembly 20 generally includes a tubular
member 36 preferably made from steel with a collar 38 securely
attached to the upper end 32 by weldment or similar coupling. Arms
28 of a yoke 30 diverge and extend outwardly from a longitudinal
axis of the lower housing assembly 20 to a distance sufficient to
receive the upper housing assembly 22 there between. Generally
arcuate openings 40 are provided at the distal ends of each arm 28
to receive a guide pin 42 attached to the upper housing assembly
22. The guide pins 42 interact with the arcuate openings 40 to
define the tilt limits of the upper housing assembly 22 with
respect to the lower housing assembly 20. In the illustrated
embodiment, arms 28 of the yoke 30 are stamped or otherwise formed
from steel bar stock and have the lower ends welded to the collar
38 to produce a rigid fork attachment at the upper end 32 of the
lower housing assembly 20. Additional information and alternatives
on the nature of the pivotal coupling between the upper housing
assembly 22 and the lower housing assembly 20 are disclosed in U.S.
Pat. No. 5,899,487, granted May 11, 1999.
[0031] Referring to the embodiment shown in FIGS. 2 and 3, the
lower and upper housing assemblies 20 and 22, respectively, are
interconnected by locking mechanism 50, preferably at points
vertically offset from the horizontal mid-line of the steering
column assembly 10, and most preferably at a point farthest from
the pivot access defined by pins 26. The upper housing assembly 22
has at least one, and preferably two flanges 52 extending generally
perpendicular at a point proximate the lower end 24 to define a
bracket. A similar structure extends perpendicular from tubular
member 36 or from collar 38 generally identified by reference
numeral 54. Attached to bracket 54 by a pin 56, and centered
between bushings 58, is one end of the locking mechanism 50. The
opposite end of the locking mechanism 50 is pivotally coupled to
bracket 54.
[0032] FIG. 4 schematically illustrates an embodiment of a locking
mechanism 50 used in combination with the instant invention.
Locking mechanism 50 is preferably a fluid-locking mechanism having
a housing 66, preferably in the shape of a right circular cylinder
closed at end 78, and having an opening 82 at an opposite end 80 of
sufficient diameter to permit the passage of shaft 62 there
through. The central or intermediate portion 84 of housing 66 has a
reduced intermediate portion (RIP) to create a constriction
generally uniformly around shaft 62. The specific dimension of RIP
84 will vary depending upon the diameter of shaft 62. RIP 84
essentially divides the housing 66 into two chambers 89 and 90,
each containing a respective piston 68 and 70. Pistons 68 and 70
each have a diameter substantially equal to the interior diameter
of the respective chambers. 0-rings or similar acting seals 91 may
extend around the circumference of each piston 68 and 70 to form a
tight seal with the interior wall 92 of the chambers 89 and 90. A
specific volume is defined between the interior surfaces 94 and 96
of the pistons 68 and 70, respectively, and the interior wall 92.
Disposed within this volume is a non-Newtonian flow fluid 97 such
as that disclosed in any one of U.S. Pat. Nos. 5,277,281;
5,284,330; 5,492,312; 5,816,372; and 5,711,746, all assigned to the
Lord Corporation. The portions of the respective chambers outboard
of the pistons 68 and 70 may be filled with ambient air passing
through holes 98 extending through the walls of ends 78 and 80.
[0033] Disposed around housing 66 adjacent RIP 84 is a device for
generating a magnetic field within the interior of the housing 66
and particularly across the inside diameter of RIP 84. In one
embodiment, the device 84 includes a electromagnet coil 85 operably
connected by conductors 86 to a power supply 87. The flow of
current through conductors 86 and electromagnet coil 85 is
controlled by a switch 88 mounted in either the steering wheel, or
a module mounted in or near the column and possibly activated by a
lever. The actual mounting method or location is not important so
long as it is reasonably accessible by the operator. In this
embodiment, depression of switch 88 interrupts the power to
electromagnet coil 85. Alternatively, the device surrounding RIP 84
may include a split annular magnet. Each half of the magnet would
be coupled to a mechanical linkage which would move each magnet
toward or away from RIP 84 to engage and disengage the mechanism.
In yet another form, permanent magnets may be mounted around RIP 84
of sufficient shape and size to produce a magnetic field or flux
across the inside of RIP 84. Arranged around the outside of the
magnets may be a wire coil similar to 85 coupled to a circuit by
conductors. The circuit may be designed such that when activated,
the electromagnetic force produced by the electromagnet coil 85
would counter the magnetic field produced by the magnets, canceling
each other to produce a field force region across RIP 84, and
allowing the fluid to move between the chambers.
[0034] All forms of the device are preferably operably connected to
a crash sensor to interrupt the supply of power, disengage or
neutralize the magnets to unlock the mechanism. In this manner, a
substantial portion of the impact could be absorbed by the
mechanism rather than by the occupant.
[0035] In operation, a bias on conductors 86 produced by the power
supply 87 causes electromagnet coil 85 to produce a magnetic field
across the non-Newtonian flow fluid in chambers 89 and 90 and most
particularly across the interior of the restriction produced by RIP
84 and the intermediate portion of shaft 62. The field causes the
fluid within that region to alter state sufficient to prevent the
fluid to pass through the RIP 84, and locks pistons 68 and 70 in
place. This magneto-rheological condition firmly fixes the relative
position of the shaft 62 with respect to the housing 66 which in
turn fixes the relative position of the upper housing assembly 22
with respect to the lower housing assembly 20. In order to change
the relative position of the upper housing assembly 22, the
operator depresses switch 88, a lever, or other input device to
interrupt the field across RIP 84 and allowing the fluid to change
state and flow through the passages defined between RIP 84 and
shaft 62. By permitting the pistons 68 and 70 to translate within
the respective chambers 89 and 90, the operator can then change the
relative position of the upper housing assembly 22 with respect to
the lower housing assembly 20. Releasing the switch 88 restores the
magnetic field which then in turn prevents the flow of fluid
between the respective chambers 89 and 90. In the case of an
electromagnet, the force necessary to change the position of the
pistons 68 and 70 may be varied--in essence fine tuning the locking
mechanism 50. Resistance could be varied by changing the volume or
size of the passage through which the fluid migrates as the piston
moves. Other available modifications include changing the diameter
of the pistons 68 and 70, or changing the diameter of the piston
passing through the RIP 84. A change in one or more of these
elements produces a change in the amount of force necessary to move
the piston and attached shaft 62.
[0036] FIG. 5 illustrates an alternate embodiment of the locking
mechanism 50 using a single piston design 150. The single piston
design 150 includes a shaft 162 having a connector 160 at one end
which is configured to be coupled to brackets 52 or 54 using the
same type of pin 56 and bushing 58 arrangements described earlier.
The opposite end of the shaft 164 terminates in piston 168 which
may include a coil of wire to form an electromagnet coil 185. The
leads from the electromagnet coil 185 may extend up through a
central hollow core 163 of the shaft 162 and exit a port 165
proximate the connector 160. There the conductors 186 are
interconnected to a switch 189 and a power supply 187 which
selectively energizes the electromagnet coil 185.
[0037] Piston 168 and a portion of the shaft 162 are disposed
within a chamber 188 defined by housing 166. The external diameter
of the piston 168 may vary in dimension from a size substantially
equal to the inside diameter of the chamber 188 or be of a lesser
size to control the dimension or space between the perimeter of the
piston 168 and the interior wall 192 (hereafter the "perimeter
volume") which provides the same function as RIP 84 above. Chamber
188 to the housing 166 is filled with the non-Newtonian flow fluid.
The entire housing 166 is preferably sealed including the passage
through which shaft 162 extends in order to prevent the fluid from
leaking. Although single seals are shown in the drawing figure, it
is anticipated that a number of redundant seals and bushings may be
used to retain the fluid within the chamber 188 and prevent a
robust seal.
[0038] With the two connectors 160 and 174 pivotally secured to the
respective brackets 52 and 54, and with a bias supplied over
conductors 186 to energize electromagnet coil 185, the
non-Newtonian fluid is unable to pass between the perimeter of the
piston 168 and the interior wall 192 creating a condition where the
piston 168 and shaft 162 are rigidly secured with respect to the
housing 166. Upon the operator's selection and depression of switch
188 and interruption of the power along conductors 186, the fluid
state changes and passes about the periphery of the piston 168 to
permit a change of position of the column. Although not shown, it
is anticipated that piston 168 may substantially extend across and
fill the interior of the housing 166. In order to permit the
passage of the fluid, ports may extend through the piston which
could be metered using jets to adjust the resistance.
[0039] In both of the embodiments described above, the locking
device is functioning in a Coulomb or Bingham lock, i.e., this
configuration approximates an ideal lock in which the force
generated is independent of piston velocity and large forces can be
generated with low or zero velocity. This independence improves
controllability of the lock making the force a function of the
magnetic field strength, which is a function of the current flow in
the circuit or the field strength produced by an adjacent magnet.
In basic terms, the flow of magnetic flux is dependent on several
factors in the flow path. The minimum lateral cross-sectional area
of the piston (68, 70 or 168) within the windings of the
electromagnet coil 185; the minimum lateral cross-sectional area of
magnetically permeable material finding a return path from magnetic
flux; and a surface area of the magnetic pull of the piston, all
having values as defined in U.S. Pat. No. 5,284,330.
[0040] The instant invention may also be used to reduce the
deceleration impact of the operator with the steering column in the
event of a crash. This is accomplished by interrupting the
conductors 186 using a switch operably connected to a crash sensor
in the vehicle. At the specified threshold, the sensor interrupts
the bias in the conductors 186, thus deactivating the electromagnet
coil 185 and allowing the steering column to be repositioned. In a
preferred embodiment, a pyrotechnic actuator may be attached to the
bracket 52 on the lower side of upper housing assembly 22 so in the
event of a crash, the locking mechanism 50 is de-energized and the
pyrotechnic pre-positioning system pulls the steering column
downward and away from the operator so that the air bag within the
steering wheel deploys to more fully absorb any impact.
[0041] In reference to FIG. 6, a portion of a telescoping steering
column assembly 300 is shown comprising a shaft 302 configured at
one end 304 to attach to the steering wheel. The opposite end of
the shaft terminates in a piston 306 having a diameter slightly
less than the diameter of the shaft 302. The piston 306 is coupled
to shaft 302 by a neck 308. Piston 306 and the necked-down portion
308 of shaft 302 are received in a cylinder 310 closed by seal 312
to define a fixed volume 314 similar to that defined by the housing
166 and piston 168 in the embodiment shown in FIG. 5. The volume
314 is filled with the non-Newtonian flow fluid 316 to completely
envelope the piston 306 and the portion of the shaft 302 extending
through the seal 312. The cylinder 310 may be formed in one end of
shaft 318 which forms the remaining portion of the shaft in the
upper or lower housing. To prevent rotation of shaft 302 relative
to shaft 318, splines may be provided along the upper interior or
end of shaft 318 and above neck 308. The splines would permit axial
translation, but fix the two shafts rotationally. The respective
shafts 310 and 302 are preferably journaled by bearings well known
in steering technology.
[0042] In this configuration, it is anticipated that an
electromagnetic coil 320 may be disposed on the exterior portion of
the upper end of the shaft 318 to create the magnetic flux in the
non-Newtonian flow fluid 316 disposed within the chamber 314
sufficient to prohibit the fluid from passing through or around the
perimeter of the piston 306. In the alternative, it is contemplated
that the shaft 302 may be hollow to provide a passage for
conductors to a coil formed in the interior of the piston 306 to
create the necessary magnetic flux. The circuit used may be similar
to that described above and could be used in combination with the
crash sensors so the relative telescoping position of the shaft 302
may be changed with respect to the shaft 318.
[0043] In yet another embodiment of the invention, the locking
mechanism 50 may be used to control the relative height, recline
angle of a seat back 408 and seat base 400; as well as the
horizontal position of the seat with respect to the steering wheel.
FIG. 7 schematically illustrates these various other applications.
For example, the seat base 400 may be supported above a track 402
and mounted to a carriage 404 by a plurality of the locking devices
generally identified as 406. In addition, the angular position of
the seat back 408 may be controlled by a locking device 410
interconnected to the seat back 408 and the seat base 400. Lastly,
horizontal travel of the carriage may be controlled by a locking
device 412 mounted at one end to the floor or frame of the vehicle
and at the opposite end to the carriage 404. Just as in the
previous embodiments, one or all of these locking devices 406, 410,
and 412 may be used to set the relative position of the seat
components. In addition, pyrotechnic propositioning systems may be
integrated to change the position of the seat in a crash.
[0044] It was briefly mentioned above that the instant invention
may be used to reduce the impact of the occupant with the steering
wheel in the event of a crash. FIG. 8 shows, in schematic form, one
assembly for achieving that function. In this embodiment, the
locking device 550 includes a locking mechanism 552 operably
coupled by conductors 554 to a controller 556 (CLR) which, in turn,
is operably coupled to a ground 557 and a power source 555 for the
circuit. Controller 556 has a plurality of inputs, including, but
not limited to, a tilt adjustment switch 558, a weight sensor 560,
a height sensor 562, an ignition sensor 564, and a crash sensor
566. Additional sensors could include accelerometers for indicating
the direction of an impact and a sensor for measuring the speed of
the vehicle.
[0045] Controller 556 may be a microchip, programmable logic
controller, micro computer or other processor capable of utilizing
data provided by the various sensors to determine the necessary
current applied over conductors 554 to control the strength of the
magnetic field produced by locking mechanism 552. That is to say
the controller 556 would dynamically change the locking
characteristics in accordance with the various inputs so any impact
by the operator is absorbed by the column rather than the occupant.
In addition, this same circuitry could include a memory circuit for
recalling particulars about a particular incident, for example, the
system may be able to indicate whether the operator was traveling a
certain speed, and direction, and whether the seat belt was in use.
The system could also record the impact direction and force. All of
this information would be useful in determining the facts
surrounding an accident. This same controller 556 may also include
information stored by the operator on the preferred position of the
column, the control pedals, the seat position, and the like.
[0046] FIG. 9 illustrates a steering column assembly 600
incorporating in the instant invention a tilting column, as well as
a telescoping column. The steering column assembly 600 includes a
lower housing assembly 602 which is intended to be secured by
flanges 604 to a section 606 of the steering column which, in turn,
may be attached to the fire wall, dash assembly, or other rigid
structure in the vehicle. The interior of the lower housing
assembly 602 is designed to receive a telescoping inner housing
assembly or shuttle 608. The inner housing assembly or shuttle 608
is configured to slide within the lower housing assembly 602
between an extended or retracted position along an axis parallel to
the longitudinal axis of the lower housing assembly 602. Inner
housing assembly or shuttle 608 may be of a particular shape
received within a correspondingly shaped passage formed in the
interior of the lower housing assembly 602 with bearing surfaces
provided to allow a smooth translation of the inner housing
assembly or shuttle 608 with respect to the lower housing assembly
602. An end of the inner housing assembly or shuttle 608 extending
from the lower housing assembly 602 may be fitted with a pair of
brackets 612, and each disposed on opposite sides of the inner
housing assembly or shuttle 608. Each bracket 612 may be generally
L-shaped or dog-legged such that one portion of the leg 614 is
securely attached to the end of the inner housing assembly or
shuttle 608, and the other portion or leg 616 extends at an angle
to leg 614 and generally tangential to the exterior of the lower
housing assembly 602.
[0047] Pivotally coupled between the ends of legs 614 may be the
lower end 618 of the upper housing assembly 620. The coupling could
permit articulating motion of the upper housing assembly 620 with
respect to the lower housing assembly 602 about an axis generally
horizontal and defined by bolts 622. For specifics on the coupling
between the bolts 622 and the attached components, the reader is
referred to U.S. Pat. No. 5,899,497 issued on May 4, 1999. In the
embodiment shown in FIG. 9, the upper housing assembly 620 also
includes a bracket 624 of a predetermined dimension having a
plurality of cutouts 626 to receive various gauges. Also extending
from the upper housing assembly 620 proximate the lower end 618 is
a buttressed flange 628. Buttressed flange 628 is interconnected to
the lower legs 616 of each bracket 612 by a fluid locking mechanism
identified by the reference numeral 630. A more detailed
illustration of the fluid locking mechanism 630 is made with
respect to FIG. 10.
[0048] Fluid locking mechanism 630 includes a housing 632 having at
least one piston 634 slidably disposed therein to define at least
two chambers 636 and 638. Extending from the piston 634 is a piston
shaft 640 which extends from the housing 632 and terminates in a
clevis 642. The clevis 642 may be pivotally attached to the
buttressed flange 628 by one or more bolts 644 (FIG. 9). Housing
632 is also similarly pivotally attached to the ends of the legs
616 by bolts 646 extending through the legs 1616 and into mounting
plates 648 formed on the exterior of the housing 632. With the
fluid locking mechanism 630 in the unlocked state, the upper
housing assembly 620 is permitted to tilt or pivot about the
coupling point defined by bolt 622. The pivotal couplings provided
by bolts 644 and 646 permit the angular orientation of the fluid
locking mechanism 630 to vary as the upper housing assembly 620 is
moved about the pivot point.
[0049] Referring again to FIG. 10, housing 632 is preferably
cylindrical and opened at one end 650 to permit the insertion of
various components therein. A piston shaft 640 extends through a
sealed opening 652 defined in the opposite end 654 of the housing
632. Concentrically disposed in the interior wall 655 of the
housing 632, and spaced inwardly away from the interior wall 655 of
the housing 632 is an inner sleeve 656 which has an inside diameter
approximately equal to the outer diameter of the piston 634. The
inner sleeve 656 is retained in position by one or more shoulders
at each end of the housing 632 or from the end cap 658 received
within the end 650 of the housing 632. The end cap 658 is sealed in
position using C-clips and seals conventional in the art. The
interior of the housing 632, the chambers 636 and 638, and the
volume between the inner sleeve 656 and the interior wall 655 of
the housing 632 are filled with the non-Newtonian flow fluid 660.
The non-Newtonian flow fluid 660 in chamber 636 is permitted to
flow into chamber 638 through space 662 located at the ends of the
inner sleeve 656, and through the peripheral volume between the
inner sleeve 656 and the interior wall 655. The flow of fluid from
one chamber to the other may be controlled in a number of ways.
Primarily the rate of fluid exchange is determined by the size of
the smallest opening, defined by either the space 662 or the
cross-section of the peripheral passage. The locking power of the
mechanism is controlled in substantial respect by the intensity of
the magnetic field or flux across those small areas. In the instant
invention, a coil is provided which generates an electromagnetic
field upon the application of a particular current. Alternatively,
permanent magnets may be used, the field of which may be
neutralized by the application of electromagnetic field. Although
the electromagnetic field is described as occurring at one end of
the inner sleeve 656, the electromagnetic force or field may be
produced at other areas of the locking mechanism 630 to change the
flow state of the non-Newtonian flow fluid 660. For clarity, the
type of fluid used in the fluid locking mechanism is substantially
similar to the fluid described above, and available from the Lord
Corporation. By varying the magnetic flux, the flow characteristic
of the non-Newtonian flow fluid 660 is changed. In one state, the
non-Newtonian flow fluid 660 is unable to pass through the small
space 662, essentially trapping the remainder of the non-Newtonian
flow fluid 660 within the respective chambers, and fixing the
relative position of the piston 634 within the housing 632. Thus,
to change the relative tilt angle of the upper housing assembly 620
with respect to the lower housing assembly 602, the operator simply
removes the electromagnetic field present within the fluid locking
mechanism 630.
[0050] FIGS. 11 and 12 illustrate another embodiment of the fluid
locking mechanism, particularly as it applies to fixing the
translation, or telescoping position of two components--in this
case, the telescoping steering column. FIG. 11 schematically
illustrates the lower housing assembly 602 in relation to the
section 606 and the interconnecting flanges 604. Extending
longitudinally through the lower housing assembly 602 is an inner
tubular member identified by reference numeral 670 which is
configured to translate longitudinally with respect to the lower
housing assembly 602. For the purposes of illustration, inner
tubular member 670 may be equivalent to the inner housing assembly
or shuttle 608. Extending concentrically through the inner tubular
member 670 may be a telescoping shaft 672 passing through bearing
674 and extending a predetermined distance into the inner tubular
member 670. In a preferred embodiment, the portion of telescoping
shaft 672 extending within the inner tubular member 670 is splined
longitudinally. Telescopically received over the splined end is a
second shaft 676 having a female coupling complimentary in shape to
the splined end of the telescoping shaft 672. Shaft 676 is intended
to extend through the opposite end of the inner tubular member 670
and may be supported by a bearing within end 678 or elsewhere along
its length. End 678 of the inner tubular member 670 may be also
configured to be interconnected to the brackets such as 612
described above by an adapter member not shown received over the
end 678. The attachment member for interconnecting the end 678 of
the inner tubular member 670 to the brackets 612 may be of
sufficient diameter such that the brackets 612 are located
generally parallel and adjacent the exterior of the lower housing
assembly 602.
[0051] It is contemplated that lower housing assembly 602 may be
generally tubular, and substantially closed at one end 678 by an
end wall 680. The opposite end 682 may be closed by a removable end
cap 684. Both the end wall 680 and the removable end cap 684 may
have openings or passages defined therein to receive the inner
tubular member 670 there through. Conventional seals and bushings
may be provided such as 690 and 688 to provide a fluid-tight seal
around the inner tubular member 670.
[0052] Intermediate on inner tubular member 670 may be an
electromagnetic coil or magnet 692 seated in an armature 694 which
is retained generally in place by snap rings 696 seated in groves
at each end of the armature 694. In the case of a wire coil mounted
on the armature 694, a hole is provided in the armature 694 to
allow the wire leads to extend there through and through the inner
tubular member 670 for connection to the circuit. To prevent the
armature 694 from rotating around the inner tubular member 670, a
pin may be provided, extending from the inner tubular member 670,
and received in a slot formed in the underside of the armature 694
to fix the rotation of the armature 694 relative to the inner
tubular member 670. A similar arrangement may be used, if desired,
to fix the relative rotational position of the inner tubular member
670 with respect to the lower housing assembly 602. Alternatively,
mechanisms exterior of inner tubular member 670 may prevent
rotation. For example, it is contemplated that each bracket 612 may
have a slotted structure such as suggested by reference numeral 695
(FIG. 9) which rides over and is engaged by a cam such as suggested
by reference numeral 697 (FIG. 11).
[0053] Disposed within the interior of the lower housing assembly
602 may be an inner sleeve 698 which has an outside diameter
approximately equal to the inside diameter of the lower housing
assembly 602 and is positioned between the end wall 680 and the
removable end cap 684. The inner diameter of the inner sleeve 698
may vary, but in no event is it less than the outside diameter of
the armature 694 and that of the electromagnetic coil or magnet
692. In a preferred embodiment, the inside diameter of the inner
sleeve 698 is such that a small gap approximately on the order of 1
to 2 millimeters or less is present between the outside diameter of
the armature 694 and the inside diameter of the inner sleeve 698.
In this fashion, a narrow passage exists between chamber 700 and
chamber 702. The two chambers and the narrow passage
interconnecting the two chambers is filled with the non-Newtonian
fluid 704 similar to that described above.
[0054] When an electromagnetic field exists across the gap between
the chambers 700 and 702, the non-Newtonian fluid 704 within that
gap, and to a certain degree in each chamber, changes states from a
conventional fluid to a more viscous material which is unable to
flow through the gap. The particular state of fluid prevents the
exchange of fluid between the respective chambers and thus locks
the armature 694, and the inner tubular member 670 in position with
respect to the lower housing assembly 602. When the electromagnetic
field is neutralized, or removed, the non-Newtonian fluid 704
reverts to its natural state, and permitted to flow across the gap
from one chamber to the other when inner tubular member 670 is
translated. To the extent that shaft 676 also moves with respect to
the inner tubular member 670, the spline ends of shafts 676 and 672
permit the relative telescopic adjustment.
[0055] In each of the embodiments described above, it is preferred
that a nonferrous material be used for the various components which
are substantially adjacent or in close proximity to the
magnetic/electromagnetic components. The use of nonferrous
materials prevents the polarization or magnetization of those
components which would result in the continued presence of a
magnetic field, thus possibly impacting the function of the locking
mechanism. Acceptable materials would include bronze, aluminum, and
polymeric materials.
[0056] According to another embodiment of the instant invention
used to alert an operator to a safety condition, a steering column
assembly 630 such as shown in FIG. 10 is provided which includes a
lower housing assembly 602 and an upper housing assembly 620, both
interconnected in a manner such that the upper housing assembly 620
is movable with respect to the lower housing assembly 602 in a
tilting fashion, telescoping fashion, or both as described
generally above. More particularly, it is envisioned that the upper
housing assembly 620 is pivotally coupled at its lower end 618 to
the upper end of the lower housing assembly 602. Alternatively, the
upper housing assembly 620 may be attached to an inner housing
assembly or shuttle 608 which is slidably received within the lower
housing assembly 602 to permit telescopic movement of the upper
housing assembly 620. To fix the relative tilt position of the
upper housing assembly 620 with respect to the lower housing
assembly 602 may be a fluid locking mechanism 630 such as available
from the Lord Corporation and using the magneto-rheological
properties of a fluid within a linear actuator to lock
interconnected components described generally above. A separate and
independent fluid-locking mechanism such as described in FIGS. 12
and 13 may be provided to control the telescoping action of the
column.
[0057] The fluid locking mechanisms 550 and 630 are interconnected
by wire leads (554 on FIG. 8 and marked in FIG. 12) to a logic
circuit such as a controller 556 (FIG. 8) which controls the amount
of current to lock and unlock the mechanisms. Also connected to the
controller 556 by wire (copper or optical) leads are sensors 558,
560, 562, 564, 566 and 559 such as proximity sensors,
accelerometers, transducers, piezoelectric sensors and the like. In
the embodiment shown, the sensors 559, 561, and 563 are
accelerometers and/or transducers which are mounted to the steering
column in at least one orientation, and preferably along orthogonal
axes. The sensors are intended to provide dynamic feedback to the
controller 556 so the locking force of the mechanism can be
adjusted to match the natural frequency of the assembly upon the
happening of a predetermined event to alert the operator to a
specific condition. Also connected to the controller 556 are
additional sensors generally indicated by numerals 565 and 567
which are intended to detect a range of conditions, the occurrence
of which triggers the alarm to alert the operator.
[0058] It is anticipated that the sensors 565 and 567 may be
provided to measure certain conditions, such as the proximity of
the vehicle to an obstacle, or the operator's state of awareness.
For example, the sensors may be provided to monitor the operator's
eye movement as shown by sensor 565. Should a low threshold be
detected (low eye movement), the controller 556 may assume the
operator has fallen asleep or is drowsy and adjust the current to
the locking mechanism 552 such that the connection between the
upper and lower housing matches the natural frequency, waking the
operator. In addition, the controller 556 may be coupled to
distance sensors such as 567 (DIST. SENS.) which monitor the
proximity of the vehicle to other objects or reference points along
a road which results in a triggering of the "natural frequency"
alarm. Alternatively, the device under control may also produce an
audible signal when set to the natural frequency. Such audible
signals could also be used to alert the operator to the occurrence
of a condition. For example, the device may be attached to a
diaphragm or transducer or other material which resonates at a
particular audible frequency to alert the operator. For visual
signals, the locking device may be used to control the natural
frequency of a piezoelectric transducer such that when the
frequency is matched, an electrical current is generated to
illuminate an indicator or produce an audible signal.
[0059] In addition to using the natural frequency of a component or
assembly to alert the operator, the instant invention can be used
in conjunction with a component or assembly to avoid the natural
frequency. The fluid locking mechanism 630 and associated circuitry
could be implemented in a manner to couple the components such that
the natural frequency is avoided, thus producing the smooth and
desired operation of the vehicle. The implementation ofthis
assembly may also result in a reduction of the front-end
engineering cost associated with avoiding the natural frequency
problem associated with certain parts/assemblies.
[0060] The electrical circuit anticipated to be used to carry out
the instant invention can assume a wide array of configurations.
Once one of ordinary skill of the art in electrical engineering,
once in possession of the goals of the instant invention, could
produce a circuit which could receive the different outputs from
the various sensors and compare them to predetermined thresholds.
This same individual, knowing the natural frequency of the
component coupled to the magneto-rheological device, and how to
adjust the magneto-rheological device to either avoid or achieve
the natural frequency, could produce a circuit wherein the natural
frequency is avoided unless certain criterion are indicated by the
sensors.
[0061] Various changes, alternatives and modifications will become
apparent to those of ordinary skill in the art following a reading
of the foregoing description. For example, although electromagnets
have been described, it will appreciate that permanent magnets may
be utilized to provide some or all of the magnetic field. The
intensity or strength of the magnetic flux through the fluid may be
changed by altering the distance of the magnet from the RIP or
cylinder. It is further contemplated that the instant invention may
be adapted for use in controlling the rotation of a steering wheel
shaft, or similar structure using a device described in U.S. Pat.
Nos. 5,492,312; 5,711,746; and 5,816,372 issued in the name of the
Lord Corporation. With the advent of electrical steering systems,
it is also contemplated that these devices could be used to provide
adjustable tactile feedback through the steering wheel to provide
the operator with a range of steering control settings. In yet
another application, the locking mechanism may be operably coupled
to a force sensor located in the steering wheel of the vehicle via
a computer. The sensor would generate a signal which would be
processed by the computer to vary the flux in the locking mechanism
during an accident wherein the locking mechanism would accommodate
and absorb some of the energy resulting from the impact of the
occupant with the steering wheel. Lastly, a different
implementation of the locking system would include adjusting the
relative position of structures such as seats and structures such
as instrument panels and the like. It is intended that all such
changes, alternatives and modifications have come within the scope
of the foregoing description be considered as part of the present
invention.
[0062] The above description is considered that of the preferred
embodiments only. Modifications of the invention will occur to
those skilled in the art and to those who make or use the
invention. Therefore, it is understood that the embodiments shown
in the drawings and described above are merely for illustrative
purposes and not intended to limit the scope of the invention,
which is defined by the following claims as interpreted according
to the principles of patent law, including the doctrine of
equivalents.
* * * * *