Abstract:
An assembly is provided for fixing the position of an adjustable component ( 22 ) of a vehicle, comprising in combination a fixed reference frame ( 20 ) within the vehicle such as a dash or a firewall, an adjustable component ( 22 ) also disposed in the vehicle such as an adjustable steering column ( 10 ), pedals, or a seat. Interconnecting the fixed reference frame ( 20 ) and the adjustable component ( 22 ) is a fluid locking mechanism ( 50 ) which permits selective positioning of the adjustable component relative to the fixed reference frame ( 20 ) and holds the adjustable component ( 22 ) in position. The fluid locking mechanism ( 50 ) is preferably a non-Newtonian flow fluid locking mechanism which uses a magneto-rheological fluid ( 97 ) to fix the position of the adjustable component ( 22 ) in place once the desired position is selected. To provide additional safety for the vehicle occupants, the fluid locking mechanism may be controlled by an electrical microprocessor ( 556 ) or circuit which adjusts the locking strength of the fluid locking mechanism ( 50 ) based upon user inputs and dynamic events.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from and is a continuation of PCT application serial number PCT/US99/30431, filed Dec. 20, 1999, which claims priority from U.S. provisional patent application Ser. Nos. 60/113,084 filed Dec. 21, 1998, and 60/164,438, filed Nov. 9, 1999, the contents of which are incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to devices for adjusting the position of one object relative to another and more particularly to a fluid-locking mechanism for fixing the position of one object relative to another, such as automobile seats, control pedals, the tilt and telescope position of a steering column, and the like. 
   2. Discussion of the Related Art 
   Traditionally, adjustable components in a vehicle have been temporarily fixed in position using mechanical locking systems. Such systems included some pawl, detent, or similar structure engaging a slot tooth, or similar structure. This has certainly been the case with adjustable vehicle steering columns. To better accommodate different operators and to make it more comfortable to operate the vehicle, articulated and telescoping steering columns, adjustable seats, and more recently, adjustable control pedals, have been devised so that the user orient the controls to positions best suited for their personal needs and comfort. The ability to adjust the relative position of a vehicle control element for the operator has been recognized as important in reducing driver fatigue and improving overall control of the vehicle. However, the mechanisms used to provide the adjustment over a limited range of positions; were subject to mechanical failure or wear, and were expensive to manufacture resulting in higher costs. Furthermore, once the particular control or object was in position, it remained fixed in an accident and presented a hazard to the operator. The instant invention provides an infinite number of adjustment positions, utilizes fewer mechanical components than prior devices resulting in lower costs, and permits repositioning of the objects in the event of an accident to reduce the chance of injury or death. 
   SUMMARY OF THE INVENTION 
   In a broad form of the invention, an apparatus is provided for interconnecting two objects together which permits the relative position of the two objects to be adjusted while the device is in a first state, but fix the relative position of the two objects while the device is in a second state. More particularly, 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 the area including 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. 
   In another form, the apparatus embodying the invention is used to adjustably fix the relative position of a steering column. 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, telescope and rotate 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 producing a magnetic field condition around at least a portion of the non-Newtonian flow fluid-locking mechanism for selectively activating and deactivating the fluid-locking mechanism. 
   In another form of the invention, the non-Newtonian flow fluid-locking mechanism includes a cylinder which is attached to one of the upper and lower housing assemblies. Received in sliding engagement within the cylinder is at least one piston mounted to a shaft which extends from the cylinder and is attached to an opposite one of the upper and lower housing assemblies. Filling the cylinder and sealed, therein is a non-Newtonian flow fluid whose flow characteristics are selectively altered under the influence of a magnetic field. When a magnetic field is absent or weak, the fluid flows permitting the piston in the cylinder to move, and change the relative position of the upper housing assembly in relation to the lower housing assembly. When a magnet field of predetermined strength is present within the fluid, the fluid flow-state is altered, fixing the piston within the cylinder and thus the relative position of the upper housing assembly to the lower housing assembly. Mechanisms for generating or neutralizing a magnetic field within the fluid include permanent magnets, electro-magnets, wire coils, or combinations thereof. 
   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. 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 to properly position the operator in an ergonomic or comfortable position. 
   The advantages provided by the instant invention include a method and apparatus for selectively fixing the relative position of one object to another. Examples include changing the tilt angle and/or longitudinal position of a steering wheel with respect to the steering column. The compact nature of the instant invention reduces manufacturing times and costs associated with assembly because complex stampings, pawls, and slots are eliminated, resulting in fewer parts than conventional adjustable steering column assemblies, translating into lower cost. Additionally, the mechanism easily interfaces with other safety mechanisms to permit repositioning of the vehicle control components in the event of a crash to reduce the risk of injury to the operator. The mechanism may be adjusted to absorb some of the impact by the operator to reduce injury, or rapidly fall away from the operator to reduce the risk of contact entirely. It is contemplated that pre-positioning devices such as pyrotechnic actuators may be used in combination with this invention to reposition vehicle components such as the steering wheel and column in the event of an accident. 
   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 
       FIG. 1  is a schematic diagram of one environment of application of the instant invention; 
       FIG. 2  is an enlarged elevation view of the invention shown in  FIG. 1 ; 
       FIG. 3  is a bottom plan view of the invention shown in  FIG. 2 ; 
       FIG. 4  is a schematic section view of one embodiment of the invention shown in  FIGS. 2 and 3 ; 
       FIG. 5  is a schematic section view of an alternate embodiment of the invention shown in  FIGS. 2 and 3 ; 
       FIG. 6  is a schematic section view of on embodiment of the invention in a telescoping assembly; 
       FIG. 7  is a schematic view of another application of the instant invention; 
       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; 
       FIG. 9  is an oblique view of a tilting and telescoping steering column employing other embodiments of the instant invention; 
       FIG. 10  is an elevation section view of the invention shown in  FIG. 9 ; 
       FIG. 11  is an oblique view of an embodiment of the instant invention used for translation of components; 
       FIG. 12  is a longitudinal section view of the invention shown in  FIG. 11 ; and 
       FIG. 13  is an enlarged view of a portion of  FIG. 12 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   For purposed 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. 
   The instant invention has application to substantially any situation where it is desired to adjustably position one component relative to another. For the sake of simplicity, the following description is made in reference to applications in a vehicle, and more to a steering column where it is common to provide for rotation (tilt) and/or translation (telescoping) movement of one component (the steering wheel) relative to a fixed reference frame such as a panel, a floorboard, a vehicle frame, a brace, a strut, or the lower housing of an adjustable steering column intended to remain stationary under normal operating conditions. Adjustable control components in addition to the steering column include a brake pedal, a clutch pedal, a gas pedal, a seat bottom, a seat back, a headrest, and an armrest. 
   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  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. The upper portion of the steering column assembly  10  ( FIG. 2 ) includes a stationary lower housing assembly  20  interconnected to the upper housing assembly  22  in a manner to permit articulation or tilting of the upper housing assembly relative to the lower housing assembly, translation or telescoping motion of the upper housing assembly relative to the lower housing assembly, 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 fixed stationary lower housing  20 . The pivot axis defined by pins  26  is preferably substantially horizontal to provide for a limited arc of rotation in a vertical plane. 
   The upper and lower housing assemblies  20  and  22  of the steering column assembly  10  enclose a series of interconnected rotatable shafts (not shown) connected at one end to the steering wheel assembly and at an opposite end to a steering gear box. A universal joint or similar coupling interconnects the shafts to permit tilt movement of the upper housing  22  relative to lower housing  20 . A telescoping shaft may be attached to the upper shaft to permit longitudinal adjustment of the steering column assembly  10 . 
   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 to a distance sufficient to receive the upper housing  20  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  22 . The guide pins  42  interact with the arcuate openings  40  to define the tilt limits of the upper housing with respect to the lower housing. 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  20 . Additional information and alternatives on the nature of the pivotal coupling between the upper housing  22  and the lower housing  20  are disclosed in U.S. Pat. No. 5,899,487, granted May 11, 1999, the contents of which are incorporated in their entirety herein by reference. 
   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, and most preferably at a point far from the pivot access defined by pins  26 . The upper housing  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  52  by a pin  56  (see  FIG. 2 ) is one end of the locking mechanism  50 . The opposite end of the locking mechanism  50  is pivotally coupled to bracket  54 . 
     FIG. 4  schematically illustrates an embodiment of a fluid-locking mechanism  50  used in combination with the instant invention. Locking mechanism  50  includes housing or cylinder  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 piston 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. O-rings or similar acting seals  91  may extend around the circumference of each piston 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 disclosures of which are incorporated herein by reference. 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 . 
   Disposed around cylinder 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 includes a wire coil  85  operably connected by conductors  86  to a power supply  87 . The flow of current through conductors  86  and coil  85  is controlled by a switch  88  mounted either in 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 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 coil would counter the magnetic field produced by the magnets, canceling each other to produce a field-free region across RIP  84 , and allowing the fluid to move between the chambers. 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. 
   In operation, a bias on conductors  86  produced by the power supply  87  causes electromagnet  85  to produce a magnetic field within the non-Newtonian flow fluid  97  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 a flow-state sufficient to prevent the fluid from passing through the RIP, and locks pistons  68  and  70  in place. This magneto-rheological condition firmly fixes the relative position of the shaft with respect to the housing which in turn fixes the relative position of the upper housing  22  with respect to the lower housing  20 . In order to change the relative position of the upper housing, 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 to translate within the respective chambers, the operator can then change the relative position of the upper housing  22  with respect to the lower housing  20 . Releasing the switch  88  restores the magnetic field which then in turn prevents the flow of fluid between the respective chambers. In the case of an electro-magnet, the force necessary to change the position of the pistons may be varied, in essence fine tuning the locking mechanism. 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, or changing the diameter of the shaft  64  passing through the RIP. A change is one of more of these elements produces a change in the amount of force necessary to move the piston and attached shaft. 
     FIG. 5  illustrates an alternate embodiment of the fluid-locking mechanism  150  using a single piston design. The single piston design 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 arrangement described earlier. The opposite end of the shaft  164  terminates in piston  168  which may include a coil of wire to form an electromagnet  185 . The leads from the coil 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 coil  185 . 
   Piston  168  and a portion of the shaft  162  are disposed within a chamber  188  defined by right circular cylinder  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 above. Chamber  188  of the housing  166  is filled with the non-Newtonian flow fluid. The entire chamber  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 provide a robust seal. 
   With the two connector ends  160  and  174  pivotally secured to the respective brackets  52  and  54 , and with a bias supplied over conductors  186  to energize coil  185 , the non-Newtonian fluid is unable to pass through the perimeter volume creating a condition where the piston  168  and shaft  162  are rigidly secured with respect to the cylinder or housing  166 . Upon the operator&#39;s selection and depression of switch  189  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 cylinder of 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. 
   In both of the embodiments described above, the locking device is functioning in a Coulomb or Brigham 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 head ( 68 ,  70  or  168 ) within the windings of the 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 of which have values as defined in U.S. Pat. No. 5,284,330. 
   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 circuit using a switch operably connected to a crash sensor in the vehicle. At the specified threshold, the sensor interrupts the bias in the circuit, thus deactivating the electromagnet 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  22  so in the event of a crash, the non-Newtonian flow fluid-locking mechanism is de-energized and the pyrotechnic pre-positioning system pulls the steering column downward and away from the operator so that the airbag within the steering wheel deploys to more fully absorb any impact. 
   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  303  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 head  306  and the neck  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 cylinder  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 head  306  and the portion of the shaft  302  extending through the seal  312 . The cylinder housing  310  may be formed in one end of solid shaft member  318  which forms the remaining portion of the shaft in the upper or lower housing. To prevent rotation of shaft  302  relative to lower 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 shaft  302  within cylinder  310  is preferably journaled by bearings well known in steering technology. 
   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 fluid  316  disposed within the chamber  314  sufficient to prohibit the fluid from passing through or around the perimeter of the piston  308 . 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 that provide data so the relative telescoping position of the shaft  302  may be changed with respect to the lower shaft  318 . 
   In yet another embodiment of the invention, the non-Newtonian flow fluid locking mechanism may be used to control the relative height, recline angle of a seat back and seat base; 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 back  408  and the 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. 
   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 coil  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  559  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 for measuring the speed of the vehicle. 
   Controller  556  may be a microchip, programmable logic controller, micro computer or other processor capable of receiving 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 coil  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 by the occupant. In addition, this same circuitry could include 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. 
     FIG. 9  illustrates a steering column assembly  600  incorporating [in] the instant invention in 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 rigidly secured 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  602  between an extended or retracted position along an axis parallel to the longitudinal axis of the lower housing assembly  602 . Shuttle  608  may be of a particular shape received within a correspondingly shaped passage formed in the interior of the lower housing assembly with bearing surfaces provided to allow a smooth translation of the inner housing with respect to the lower housing. An end of the inner housing extending from the lower housing assembly  602  may be fitted with a pair of brackets  612 , each disposed on opposite sides of the inner housing. 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  608 , and the other portion of leg  616  extends at an angle to leg  614  and generally tangential to the exterior of the lower housing assembly  602 . 
   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 and the attached components, the reader is referred to U.S. Pat. No. 5,899,497 issued on May 4, 1999, the specification of which is incorporated herein by reference. 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 housing  620  proximate the lower end  16  is a buttressed flange  628 . Flange  628  is interconnected to the 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 . 
   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 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  (See  FIG. 9 ). Housing  632  is also similarly pivotally attached to the ends of the legs  616  by bolts  646  extending through the legs 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  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  620  is moved about the pivot point. 
   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  654  of the housing  632 , and spaced inwardly away from the interior walls 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 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 inner wall  654  of the housing are filled with the non-Newtonian flow fluid  660 . The fluid in chamber  636  is permitted to flow into chamber  638  through perforations or spaces  662  located in sleeve  656 , and through the peripheral volume between the sleeve  656  and the inner wall  654 . 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 either by the passages  662  or the cross-section of the peripheral passage between inner wall  654  and sleeve  656 . The locking power of the mechanism is controlled in substantial respect by the intensity of the magnetic field or flux existing in those small areas. In the instant invention, a coil  664  is provided which generates an electromagnetic field upon the application of a particular current. Alternatively, permanent magnets may be used in place of coil  664 , the field of which may be neutralized by the application of an electromagnetic field by a coil proximate the magnets. Although the electromagnetic field is described as occurring at one end of the sleeve  656 , the electromagnetic force or field may be produced at other areas of the locking mechanism to change the flow state of the 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 mentioned above. By varying the magnetic flux, the flow-state or characteristic of the fluid  660  is changed. In one state, the fluid is unable to pass through the small perforations  662 , essentially trapping the remainder of the fluid within the respective chambers, and fixing the relative position of the piston  634  within the housing. Thus to change the relative tilt angle of the upper housing  620  with respect to the lower housing assembly  602 , the operator simply removes the electromagnetic field present within the fluid locking mechanism. 
     FIGS. 11 through 13  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 lower rigid structure  606  and the interconnecting flanges  604 . Extending longitudinally through the lower housing  602  is an inner tubular member identified by reference numeral  670  which is configured to translate longitudinally with respect to the lower housing  602 . For the purposes of illustration, component  670  may be equivalent to the shuttle or inner housing assembly  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 tubular member  670 . In a preferred embodiment, the portion of shaft  672  extending within the tubular housing  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 shaft  672 . Shaft  676  is intended to extend through the opposite end of the tubular member  670  and may be supported by a bearing within end  678  or elsewhere along its length. End  678  of the 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. The attachment member for interconnecting the end  678  of the 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 the housing  602 . 
   It is contemplated that housing  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 end cap  684  may have openings or passages defined therein to receive the tubular member  670  there through. Conventional seals and bushings may be provided such as  688  and  690  to provide a fluid-tight seal around the tubular member  670 . 
   Intermediate on tubular member  670  ( FIGS. 12 and 13 ) 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  679  is provided in the armature to allow the wire leads  699  to extend there through and through the tubular members  670  for connection to the circuit. To prevent the armature from rotating around the tubular member  670 , a pin  691  may be provided, extending from the tubular member  670 , and received in a slot  693  formed in the underside of the armature to fix the rotation of the armature relative to the 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 housing  602 . Alternatively, mechanisms exterior tube  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 ). 
   Disposed within the interior of the housing  602  shown in  FIG. 13 , may be an inner sleeve  698  which has an outside diameter approximately equal to the inside diameter of the housing  602  and is positioned between the end wall  680  and the end cap  684 . The inner diameter of the sleeve  698  may vary, but in no event is it less than the outside diameter of the armature  694  and that of the magnet or electromagnetic coil  692 . In a preferred embodiment, the inside diameter of the 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 sleeve  698 . In this fashion, a narrow passage exists between the 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. 
   When an electromagnetic field exists across the gap between the chambers  700  and  702 , the 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 flow-state of the fluid prevents the exchange of fluid between the respective chambers and thus locks the armature, and the tubular member  670  in position with respect to the housing  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 tabular member  670  is translated. To the extent that shaft  676  also moves with respect to the tubular housing  670 , the spline ends of shafts  676  and  672  permit the relative telescopic adjustment. 
   In each of the embodiments described above, it is preferred that a non-ferrous material be used for the various components which are substantially adjacent or in close proximity to the magnetic/electromagnetic components. The use of non-ferrous 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. 
   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 be appreciated 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 has come within the scope of the foregoing description be considered as part of the present invention.