Infinitely adjustable track locking mechanism

A mechanism for selectively locking a stationary element and a movable element mounted on the stationary element. The mechanism comprises a pawl block mounted within a casing for sliding movement in opposite first and second directions along a first axis substantially transverse to an engagement surface on the stationary element. The pawl block has a substantially "V"-shaped cavity defined by two ramp surfaces which, together with the engagement surface, define a substantially triangular recess. A striated roller member is mounted within the recess for simultaneous circumferential engagement with the engagement surface and at least one of the inclined ramp surfaces when the pawl block is in its locking configuration. A wedge block is movable in opposite third and fourth directions along a second axis generally transverse to the first axis, between a blocking position, whereat the wedge block wedgingly engages the pawl block into the locking configuration, and a withdrawn position, whereat the wedge block is removed from such wedging engagement so as to permit movement of the pawl block from the locking configuration to an unlocked configuration.

FIELD OF THE INVENTION 
The present invention relates to manually operated mechanisms for 
selectively locking in infinitely adjustable relation to each other, a 
stationary element and a movable element co-operatively mounted on the 
stationary element, and more particularly to manually operated vehicle 
seat track slides having at least one stationary track member and one 
movable track member to be selectively locked in infinitely adjustable 
relation to each other. 
BACKGROUND OF THE INVENTION 
Many manually adjustable prior art vehicle seats have incrementally 
adjustable vehicle seat track members on which the entire seat assembly 
slides between a plurality of discrete fore and aft positions, wherein two 
track members are locked in place with respect to each other by a separate 
external locking means having teeth that protrude into aligned apertures 
in one or both of the two track members. There are, however, numerous 
problems associated with incrementally adjustable vehicle seat tracks and 
the locking mechanisms therefor, not the least of which is partial 
locking. Partial locking occurs when the teeth of the external locking 
means do not fully engage the apertures in the tracks on one or both of 
the inboard and outboard seat tracks. This problem is particularly acute 
in modern vehicle seating installations which utilize an integrated 
restraint system ("I.R.S."), where at least one anchor point for the 
passenger seat belts is attached to the seat assembly for adjustably 
sliding movement with the vehicle seat. I.R.S. arrangements typically 
require that both of the inboard and outboard seat tracks to be 
simultaneously fully locked under crash-like conditions, so as to safely 
handle the increased loading applied to the seat tracks by the seat belt 
attachments. 
To ensure such simultaneous full locking, manually actuated, infinitely 
adjustable seat track locking mechanisms have recently found favour. These 
devices have no discrete teeth or detent members which engage slots in the 
seat track slides etc. Rather, infinitely adjustable seat track locking 
mechanisms typically use spring clutches or other devices to lock at any 
position upon release of the actuation mechanism by the user. Infinitely 
adjustable seat track locking mechanisms have found such favour despite 
their increased cost and complexity because they substantially solve the 
problem of partial locking discussed above, and offer more adjustment 
possibilities to the seat track designer, and ultimately the seat 
occupant. Also, generally speaking, infinitely adjustable seat track 
locking mechanisms are capable of providing for higher loading before 
failure under crash-like deceleration conditions, and substantially free 
up the interior space of the vehicle seat track slide to allow use of this 
space for other purposes (such as rollers or anti-rattle mechanisms). 
One example of a recent infinitely adjustable locking mechanism is 
disclosed in U.S. Pat. No. 5,183,236 (Droulon), which patent is to a 
locking mechanism for rectilinear or circular displacement mechanical 
jacks. A mechanical jack is a broad term used in the Droulon patent to 
refer to a type of mechanism that has two co-operating members that are 
movable one with respect to the other, and that permits selective locking 
of the two members in chosen displacement one to the other. 
In one embodiment of the Droulon patent, a casing is slidably mounted on a 
jack rod, which jack rod is part of the vehicle seat, for relative sliding 
movement of the casing along the jack rod. The casing is also operatively 
mounted in secure relation to the vehicle. A "V"-shaped pawl block is 
retained within the casing for movement between a locking position and an 
unlocking position, as will be described subsequently. The pawl block has 
a pair of inclined ramp surfaces that define a "V"-shaped cavity, which 
"V"-shaped cavity, together with an engagement surface on the rod, define 
a substantially triangular recess. A striated roller member is rotatedly 
mounted within the triangular recess for rolling contact with the 
engagement surface on the rod. 
The Droulon pawl block has first and second sloped side surfaces that 
converge and join at a flat end surface. The first sloped side surface 
abuts against a co-operating corresponding sloped abutment surface on the 
casing. The second sloped side surface is in intimate supported contact 
with a rotatable generally round cam member, which rotatable cam member is 
also retained within the casing for movement between a blocking position 
and releasing position. In the blocking position, the cam member retains 
the pawl block in its locking position, and in the releasing position, the 
cam member retains the pawl block in its unlocking position. In either the 
locking or unlocking position of the pawl block, the pawl block is 
angularly pinched in unstable rockable relation between the generally 
round cam member and the sloped abutment surface of the casing. 
The Droulon infinitely adjustable locking mechanism works in the following 
manner. In its locking position, the pawl block is wedged between the cam 
member and the sloped abutment surface of the casing, and is forced into 
its locking position whereat the striated roller is forced into intimate 
engagement with the engagement surface on the rod. The striated roller is 
trapped in centred relation within the triangular recessed defined by the 
engagement surface and the pawl block. When an accelerative or 
decelerative force is applied to the vehicle seat, the striated roller 
attempts to roll along the engagement surface of the rod; however, the 
striated roller becomes pinched between the rod and the respective 
inclined ramp surface of the pawl block. Accordingly, the striated roller 
cannot move along the rod, and thus the casing and the rod are locked with 
respect to each other. 
In its unlocking position, the Droulon cam member is rotated so that the 
pawl block is not pushed into its locked position. A spring member biases 
the pawl block to its unlocking position, whereat the striated roller does 
not contact, or at least loosely contacts, the engagement surface on the 
rod. The casing and the rod may then be moved relative to one another. 
Once in a desired position, the cam member is returned to its blocking 
position at the pawl block is forced to its locking position, whereat the 
striated roller is again brought into locking engagement with the 
engagement surface of the rod, thus locking the casing and the rod with 
respect to each other. 
While the Droulon device makes a definite improvement in the art, it has 
been found that the generally round cam member tends to act as a pivot 
point for the pawl block. Accordingly, there tends to be relative 
movement, and therefore looseness, between the pawl block and the sloped 
side surface, and also between the pawl block and the striated roller. 
This looseness between adjacent parts is known in the art as "chuck". The 
problem of chuck arises inherently in any mechanical vehicle seat locking 
device, and is the result of the clearances that are necessarily a part of 
any device containing mass-produced parts adapted to undergo relative 
movement. Chuck is a highly undesirable characteristic in automobile seat 
back hinges, for both safety and aesthetic reasons. 
The Droulon mechanism exhibits a higher degree of chuck than is ideally 
desirable because a generally round cam member is used to control the 
positioning of the pawl block, which cam acts as a pivot point for the 
pawl block. This imparts a first source of chuck into the Droulon device. 
It can be seen that there is a second source of chuck imparted to the 
Droulon device on account of the clearances between the first sloped side 
surface of the pawl block and the co-operating, correspondingly sloped, 
abutment surface of the casing. There is a third source of chuck in 
relation to lost motion between the striated roller and the remaining 
components of the device. These three sources of chuck are highly 
undesirable, as they stack together to cause an overall looseness in the 
operation of the locking mechanism. 
Another factor that affects the proper operation of the Droulon prior art 
locking mechanism is that it requires close manufacturing tolerances of 
the various parts that make up the locking mechanism. That is, if the 
parts have been manufactured slightly undersized, the striated roller may 
not properly engage the engaging surface on the rod, and resultingly, the 
locking mechanism may not lock the two co-operating elements with respect 
to each other. Conversely, if the parts have been manufactured slightly 
oversized, the locking mechanism may jam. The need for close manufacturing 
tolerances increases the cost and complexity of manufacture. 
Another problem associated with the Droulon type of infinitely adjustable 
locking mechanism is the tendency of the various parts, such as the cam 
member, to physically wear after a period of time. Such wear causes 
increased looseness in the mechanism and accordingly, an even greater 
amount of chuck. In extreme circumstances, a significant amount of wear of 
the various parts could mean that the striated roller does not properly 
engage the engaging surface on the rod, thus perhaps precluding the 
locking mechanism from locking the two cooperating elements with respect 
to each other. 
Another inherent problem with the Droulon mechanism is that it tends to 
lock better in one direction than in the other opposite direction. This 
directionality problem is overcome in the several illustrated embodiments 
by the inclusion of two "V"-shaped pawl blocks, each pawl block retaining 
a separate striated roller, and each pawl block abutting against opposed 
sloped sides of the casing. This solution introduces problems of increased 
degrees of chuck, increased overall size of the locking mechanism, 
increased complexity of manufacturing, and increased cost. 
It is an object of the present invention to provide a mechanism for 
selectively locking in infinitely adjustable relation to each other, a 
stationary element and a co-operating movable element, wherein chuck is 
minimized. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other, a 
stationary element and a co-operating movable element, wherein relatively 
large tolerances in the size of the parts of the mechanism are within 
acceptable safety limits. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other a 
stationary element and a co-operating movable element, wherein wear of the 
parts of the mechanism is automatically accommodated. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other a 
stationary element and a co-operating movable element, which mechanism is 
relatively simple to manufacture. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other a 
stationary element and a co-operating movable element, which mechanism is 
relatively inexpensive to manufacture. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other a 
stationary element and a co-operating movable element, which mechanism is 
relatively small in size. 
It is an object of the present invention to provide a mechanism for 
selectively locking an infinitely adjustable relation to each other a 
stationary element and a co-operating movable element, wherein the 
mechanism employs a single roller and locks equally well in opposite 
linear directions. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided a mechanism for 
selectively locking, in infinitely adjustable relation to each other, a 
stationary element and a movable element co-operatively mounted on the 
stationary element for movement in opposed first and second directions, 
the movable element having a generally planar engagement surface. The 
locking mechanism comprises: a casing rigidly mounted to the stationary 
element, the casing including a fixed abutment portion; a pawl block 
mounted within the casing and having a substantially "V"-shaped cavity 
defined by two ramp surfaces inversely inclined towards an apex of 
intersection; which inclined ramp surfaces, together with the engagement 
surface, define a substantially triangular recess. The pawl block is 
mounted within the casing, as aforesaid, so as to be slidably movable in 
opposite first and second linear directions along a first axis 
substantially transverse to the engagement surface, thereby to 
respectively increase and decrease the linear distance between the apex of 
intersection and the engagement surface. A striated roller member is 
operatively mounted on the casing, so as to be positioned within the 
substantially triangular recess for simultaneous circumferential 
engagement with the generally planar engagement surface and at least one 
of the inclined ramp surfaces, when the pawl block is moved in the first 
linear direction along the first axis to a locking configuration, and, for 
removal from such simultaneous circumferential engagement when the pawl 
block is moved in the second linear direction along the first axis to an 
unlocked configuration. A wedge block means, having a pawl block 
contacting surface and an abutment portion engagement surface, is also 
provided. The wedge block means is operatively mounted within the casing, 
so as to be movable in opposite third and fourth linear directions, along 
a second axis generally transverse to the first axis, respectively, 
between a blocking position, whereat the wedge block means is wedgingly 
engaged between a generally planar wedge-contacting surface positioned on 
the pawl block and the abutment portion of the casing so as to thereby 
urge the pawl block into the locking configuration, and a withdrawn 
position, whereat the wedge block is removed from the wedging engagement 
so as to permit movement of the pawl block from the locking configuration 
to the unlocked configuration, thereby to permit relative movement of the 
stationary and movable elements. 
Other advantages, features and characteristics of the present invention, as 
well as methods of operation and functions of the related elements of the 
structure, and the combination of parts and economies of manufacture, will 
become more apparent upon consideration of the following detailed 
description and the appended claims, with reference to the accompanying 
drawings, the latter of which is briefly described hereinbelow.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring now to FIGS. 1 and 2 of the drawings, a vehicle seat assembly, as 
indicated by the general reference numeral 21, is shown mounted on the 
floor 56 of a vehicle (not shown), with the locking mechanism of the 
present invention, as indicated by the general reference numeral 20, 
installed thereon. The vehicle seat assembly 21 shown is one of two front 
"bucket" type seats of the vehicle, and, for reference purposes herein, 
will be assumed to be the driver's seat assembly of a typical left-hand 
drive vehicle. 
FIG. 1 shows the vehicle seat assembly 21 in a generally central fore-aft 
position relative to the vehicle floor 56, which position would be a 
typical in-use position for an average sized passenger (not shown) seated 
in the vehicle seat assembly 21. FIG. 2 shows the vehicle seat assembly 21 
after the locking mechanism 20 of the present invention has been unlocked, 
and the vehicle seat assembly 21 has been moved to a forward fore-aft 
position relative to the vehicle floor 56, which position would be used 
for a short legged passenger, or, for example, to facilitate ingress into 
and egress from, or general access to, the rear seat area of a two door 
vehicle. 
As can best be understood with reference to FIG. 3, the vehicle seat 
assembly 21 is adjustably mounted in the vehicle atop a pair of seat track 
slides 23,25. The inboard seat track slide is marked in the Figures with 
reference numeral 23, while the substantially identical outboard seat 
track slide is marked with reference numeral 25. Both of the inboard 23 
and outboard 25 slides comprise a stationary vehicle seat track member 22 
and a moveable vehicle seat track member 24, which stationary 22 and 
moveable 24 vehicle seat track members are co-operatively mounted one to 
the other in a conventional manner for sliding fore-aft movement of the 
moveable vehicle seat track member 24 with respect to the stationary 
vehicle seat track member 22 in opposed first and second directions, as 
indicated by arrows "A" and "B", respectively. The stationary track member 
22 of each of the inboard 23 and outboard 25 track slides is secured to 
the vehicle floor 56 by way of front and rear leg members 27 and anchor 
bolts 29. The moveable track member 24 of each of track slides 23,25 may 
be connected to each other by way of a pair of bracing members 19, affixed 
to each of the moveable track members 24 as shown, by spot welding, or any 
other suitable affixation means. 
Each of the movable track members 24 is itself bolted or otherwise rigidly 
affixed to the vehicle seat assembly 21 by means of bolts 58 extending 
through apertures 57 positioned adjacent opposite linear ends of the 
respective movable track members 24. The bolts 58 conventionally engage 
the frame structure (not shown) of the vehicle seat assembly 21. One 
locking mechanism 20, as will be subsequently described, is installed on 
the inboard seat track slide 23 and another substantially identical 
locking mechanism 20 is similarly installed on the outboard seat track 
slide 25, so as to each engage a generally planar engagement surface 28 
positioned on an exterior surface 26 of the respective one of the moveable 
track members 24 of each slide 23,25. 
Referring now to FIGS. 3 through 10 of the drawings, the locking mechanism 
20 for selectively locking in infinitely adjustable relation to each other 
a stationary element, such as the stationary vehicle seat track member 22, 
and a moveable element, such as the moveable vehicle seat track member 24, 
is shown. 
The operative components of the locking mechanism 20 are enclosed within a 
casing, generally designated by the reference numeral 30, which casing 30 
is rigidly mounted to the stationary vehicle seat track member 22, 
externally of the stationary vehicle seat track member 22 and the moveable 
vehicle seat track member 24. It should be readily understood that the 
casing 30 could be equivalently mounted to the moveable vehicle seat track 
member 24, in which case the generally planar engagement surface 28 would 
correspondingly be positioned on the stationary vehicle seat track member 
22. 
The casing 30 has top 31a and bottom 31b wall members, two opposed side 
wall members 31c, and an end wall member 31d that acts as a fixed abutment 
portion 32. In the preferred embodiment shown in the Figures, the side 
wall members 31c and the end wall member 31d are formed as one integral 
piece, with each of the top 31a and bottom 31d wall members being separate 
plates. All of these various components of the casing 30 are removably 
secured together by four bolts 33. The abutment portion 32 is an integral 
part of the casing 30, and presents, internally of the casing 30, a 
substantially planar surface 34, as will be discussed subsequently in 
greater detail. 
A pawl block 40, preferably constructed using powdered metal casting 
techniques to achieve close manufacturing tolerances, is slidably mounted 
within the casing 30 between two parallel inner guide surfaces 36 and 37 
of the opposed casing side wall members 31c,31c. The pawl block 40 is 
slidably movable in opposite first "C" and second "D" linear directions 
along a first axis "E" which first axis "E" is substantially transverse to 
the generally planar engagement surface 28, between a locking 
configuration, as best seen in FIG. 7, and an unlocked configuration, as 
best seen in FIG. 8. Preferably, there is just enough clearance between 
the pawl block 40 and each of the two parallel inner guide surfaces 36 and 
37 so that the pawl block 40 slides readily therebetween, but is not 
loose. Clearances in the order of 0.001" to 0.004" are desirably 
attainable in this regard. 
The pawl block 40 has a substantially "V" shaped cavity 42 at one end 
thereof, and a substantially planar wedge-contacting surface 41 located on 
the opposite other end thereof. The substantially "V" shaped cavity 42 is 
defined by two ramp surfaces 44 and 45, which ramp surfaces 44 and 45 are 
inversely inclined towards an apex of intersection 46. The inclined ramp 
surfaces 44 and 45, together with the engagement surface 28, define a 
substantially triangular recess 48. Movement of the pawl block 40 along 
the first axis "E" in first direction "C" decreases the linear distance 
between the apex of intersection 46 of the two ramp surfaces 44 and 45 and 
the generally planar engagement surface 28 of the moveable vehicle seat 
track member 24, while movement of the pawl block 40 along the first axis 
"E" in the opposite second direction "D" increases this linear distance. 
A striated roller member 50 is rotatably mounted on the casing 30 so as to 
be positioned within the substantially triangular recess 48, by means of a 
centrally disposed axle means 52. The axle means 52 is preferably held in 
centred relation to the apex of intersection 46 by a pair of torsion 
springs 54. The free ends 56 of each of the torsion springs 54 engage the 
casing 30 at the heads 35 of bolts 33. The central body portion 55 of each 
of the torsion springs 54 engages a respective opposite end 53 of the axle 
means 52. Thus, the two torsion springs 54 act as a biasing means so as to 
substantially center the striated roller 50 with respect to the apex of 
intersection 46 of the two inversely inclined ramp surfaces 44 and 45. 
The striated roller 50 is further positioned within the substantially 
triangular recess 48 for simultaneous circumferential engagement with the 
generally planar engagement surface 28 of the moveable vehicle seat track 
member 24 and at least one of the inclined ramp surfaces 44 and 45 when 
the pawl block 40 is moved in a first linear direction "C" along the first 
axis "E" to a locking configuration. The striated roller member 50 is 
further positioned within the substantially triangular recess 48 for 
removal from aforesaid simultaneous circumferential engagement when the 
pawl block 40 is moved in a second linear direction "D" along the first 
axis "E" to an unlocked configuration, as best seen in FIG. 8. 
A wedge block means 60 is situated between the pawl block 40 and the 
substantially planar surface 34 of the abutment portion 32. A 
substantially planar pawl-contacting surface 62 on the wedge block means 
60 operatively contacts the substantially planar wedge-contacting surface 
41 on the pawl block 40. The wedge block means 60 also has an abutment 
portion engagement surface 64, located at its opposed other end to the 
pawl-contacting surface 62, which abutment portion engagement surface 64 
is adapted to contact the substantially planar surface 34 of the abutment 
portion 32 in force transmitting relation, relative to axis "E". 
The wedge block means 60 is also preferably constructed using powdered 
metal casting techniques to achieve close manufacturing tolerances, and is 
slidably mounted with respect to the casing 30 between two parallel guide 
surfaces 38 and 39, (which are the innermost surfaces of the opposed side 
wall members 31c of the casing 30) so as to be movable in opposite third 
"F" and fourth "G" linear directions along a second axis "H", which second 
axis is generally transverse to the first axis "E". Preferably, there is 
just enough clearance between the wedge block means 60 and each of the two 
parallel inner guide surfaces 38 and 39, so that the wedge block means 60 
slides readily therebetween, but is not loose. Clearances in the order of 
0.001" to 0.0004" are desirably attainable in this regard. The wedge block 
means 60 is movable between a blocking position, as is best seen in FIG. 
7, and a withdrawn position, as best seen in FIG. 8. In the blocking 
position, the wedge block means 60 is wedgingly engaged between the 
substantially planar wedge-contacting surface 41 and the substantially 
planar surface 34 of the abutment portion 32, so as to thereby urge the 
pawl block 40 to its locking configuration. 
In the withdrawn position, the wedge block means 60 is sufficiently removed 
from aforesaid wedging engagement between the pawl block 40 and the 
abutment surface 32, so as to permit movement of the pawl block 40 from 
its locking configuration to its unlocked configuration, thereby to permit 
relative movement of the stationary vehicle seat track member 22 and the 
moveable vehicle seat track member 24. 
The pawl-contacting surface 62 is inclined with respect to the second axis 
"H" at an acute angle ".alpha.", (see FIG. 7) which angle ".alpha." is 
greater than 0.degree., and less than about 45.degree., depending on the 
co-efficient of friction of the materials of the wedge-contacting surface 
41 and the pawl contacting surface 62. It has been found that an angle of 
about 20.degree. is preferable for this application, where powdered metal 
components are used as indicated above. In the preferred embodiment shown, 
the pawl-contacting surface 62 is preferably also inclined with respect to 
the first axis "E" at an acute angle "o", but may be oriented transversely 
to the first axis "E". 
The wedge-contacting surface 41 is inclined with respect to the second axis 
"H" at an obtuse angle of incline ".beta." that is complementary to the 
angle of incline of the pawl-contacting surface 62, such that the 
wedge-contacting surface 41 is also inclined with respect to the second 
axis "H" at an angle parallel to the pawl-contacting surface 62. The 
pawl-contacting surface 62 of the wedge block means 60 and the 
wedge-contacting surface 41 of the pawl block 40 are thereby caused to 
operatively engage each other in flat surface-to-surface stable contact, 
thus precluding unwanted relative movement, and therefore, any significant 
"chuck", between the pawl block 40 and the wedge block means 60. 
Preferably, the substantially planar surface 34 of the abutment portion 32 
is substantially perpendicular with respect to the first axis "E". In this 
manner, any forces that are transmitted through the pawl block 40, and 
therefore along the direction of first axis "E", and through the wedge 
block means 60 to the abutment portion 40, would produce a reaction force 
at the substantially planar surface 34, which reaction force is oppositely 
directed parallel to the first axis "E". Thus, there is no component of 
the reaction force that acts in the fourth linear direction "G", as with 
prior art devices utilizing a rotary cam. A reaction force having a 
component that acts in the fourth linear direction "G" would cause the 
wedge block means 60 to be biased in the fourth linear direction "G" 
towards its withdrawn position. Such biasing of the wedge block means 60 
in the fourth linear direction is highly undesirable, as it would tend to 
remove the wedge block means 60 from contact with the pawl block means 40. 
Accordingly, the pawl block 40 would tend to be moved away from its 
locking configuration. 
The wedge-contacting surface 41 and the substantially planar surface 34 of 
the abutment portion 32 are generally opposed one to the other, and are 
angled with respect to each other so as to form a wedge shape, to thereby 
accommodate the wedge block means 60 in flat surface-to-surface stable 
contact between the pawl-contacting surface 62 and the wedge-contacting 
surface 41, and also between the abutment portion engagement surface 64 
and the substantially planar surface 34 of the abutment portion 32. The 
substantially planar surface 34 of the abutment portion 32 and the 
wedge-contacting surface 41 converge with respect to each other in the 
third linear direction "F", so as to accommodate the shape of the wedge 
block means 60. 
An actuation means, as indicated by the general reference numeral 70, is 
operatively connected to the wedge block means 60 to provide for selective 
movement of the wedge block means 60 in its third "F" and fourth "G" 
linear directions. The actuation means 70 comprises a sheathed cable 72, 
having a cable member 73 operatively attached at its one end 74 to the 
wedge block means 60, as can be best seen in FIGS. 7 and 8, and 
operatively attached at its opposite other end 76 to a handle means 78, as 
can best be seen in FIG. 3. The sheath 71 is threadibly engaged at one end 
75 to the casing 30, and is threadibly engaged at its opposite other end 
77 to a retaining bracket 80 attached to one of the bracing members 19 of 
the vehicle seat assembly 21, so as to permit adjustability of the 
tightness of the cable 73. Pulling on the cable member 73, moves the wedge 
block means 60 from its blocking position towards its withdrawn position 
against the biasing force of the first biasing means being coil spring 79, 
which coil spring is positioned as shown within the casing. 
In use, a user manipulates the handle means 78 by lifting the handle means 
78 in the direction indicated by arrow "I" (see FIG. 3), which lifting of 
the handle means 78 correspondingly pulls the cable means 73 of the 
sheathed cable 72, such that the wedge block means 60 is moved in the 
fourth linear direction "G" towards its withdrawn position, against the 
biasing force of the first biasing means coil spring 79. The wedge block 
means 60 is, accordingly, removed from wedging engagement between the pawl 
block 40 and the abutment portion 32 of the case 30, so as to permit 
movement of the pawl block 40 from its locking configuration to its 
unlocked configuration. In the unlocked configuration of the pawl block 
40, the linear distance between the apex of intersection 46 of the two 
ramp surfaces 44 and 45 and the engagement surface 45 is increased, to 
thereby remove the striated roller member 50 from simultaneous 
circumferential engagement with the generally planar engagement surface 28 
and at least one of the inclined ramp surfaces 44 and 45. In the preferred 
embodiment illustrated, the torsion springs 54 bias the striated roller 
member 50 towards the apex of intersection 46 of the two ramp surfaces 44 
and 45 (so as to prevent creep of the striated roller member 50), and the 
striated roller member 50 is accordingly, removed from circumferential 
engagement with the generally planar engagement surface 28. Resultingly, 
the generally planar engagement surface 28 may be moved with respect to 
the locking mechanism 20, thereby to permit relative movement of the 
stationary vehicle seat track member 22 and the moveable vehicle seat 
track member 24. Such relative movement of the stationary vehicle seat 
track member 22 and the moveable vehicle seat track member 24 corresponds 
to relative sliding movement of the vehicle seat assembly 21 between its 
various fore-aft positions. 
When the vehicle seat assembly 21 has reached a desired fore-aft position, 
the user releases the handle means 78, which handle means 78 travels in 
the direction of arrow "J" to a rest position, as caused by the first 
biasing means coil spring 79, and as assisted by gravity. Accordingly, the 
wedge block means 60 is caused to move in the third linear direction "F" 
from its withdrawn position to its blocking position. During this movement 
of the wedge block means 60 from its withdrawn position to its blocking 
position, the pawl-contacting surface 62 slides along the wedge-contacting 
surface 41 of the pawl block 40, thus causing the pawl block 40 to move 
towards its locking configuration. The pawl-contacting surface 62 of the 
wedge block means 60 and the wedge-contacting surface 41 of the pawl block 
40 remain in flat surface-to-surface stable contact one with the other 
during the movement of the pawl block means 60 from its withdrawn to its 
blocking position. In its blocking position, the pawl block 40 causes the 
striated roller member 50 to be in simultaneous circumferential engagement 
with the generally planar engagement surface 28 and at least one of the 
inclined ramp surfaces 44 and 45 to thereby preclude relative movement of 
the stationary vehicle seat track member 22 and the moveable vehicle seat 
track member 24. 
In the event of acceleration or deceleration of the vehicle having the 
vehicle seat assembly 21 therein, the corresponding rearwardly or 
forwardly directed force of inertia or momentum, as the case may be, of 
the vehicle seat assembly 21 is transferred through the moveable element 
24 to the striated roller member 50, which striated roller member 50 is 
pinched between the generally planar engagement surface 28 and the 
respective of the two ramp surfaces 44 and 45, depending on the direction 
of the force. The force from the striated roller member 50 is transmitted 
to the respective one of the two ramp surfaces 44 and 45. Due to the 
sloped orientation of the ramped surfaces 44 and 45, a portion of the 
force is transmitted through the pawl block 40 to the respective of the 
inner guide surfaces 36 and 37, and to the stationary vehicle seat track 
member 22, and the remaining portion of the force is transmitted through 
the pawl block 40 to the wedge block means 60 and ultimately to the casing 
30 at the abutment portion 32 thereof. The flat surface-to-surface stable 
contact between the wedge-contacting surface 41 of the pawl block 40 and 
the pawl-contacting surface 62 of the wedge block means 60 ensures that 
there is no significant relative movement, and therefore no looseness or 
"chuck", between the wedge block means 60 and the pawl block 40, unlike 
prior art devices utilizing cams. 
It will be understood that numerous variations as will occur to those 
skilled in the art may be made to the above-described apparatus without 
departing from the claimed scope of the invention. For example, in an 
alternative embodiment of the present invention (not shown), it is 
envisioned that the wedge-contacting surface 41 could be oriented 
generally perpendicularly to the first axis "E" and that the substantially 
planar surface 34 of the abutment portion 32 could be inclined with 
respect to the first axis "E". The wedge-contacting surface 41 and the 
substantially planar surface 34 of the abutment portion 32 would remain 
generally opposed one to the other, and would be angled with respect to 
each other so as to form a wedge shape, to thereby accommodate the wedge 
block means 60 in flat surface-to-surface stable contact between the 
pawl-contacting surface 62 and the wedge-contacting surface 41 and also 
between the abutment portion engagement surface 64 and the substantially 
planar surface 34 of the abutment portion 32. 
In a further alternative embodiment of the present invention (not shown), 
it is envisioned that the stationary element and the moveable element 
could be pivotally attached one to the other, such as in a vehicle seat 
hinge, with the generally planar engagement surface essentially forming a 
curved plane coincident with a radius centered on the point of pivotal 
attachment of the stationary and pivotal elements. In yet a further 
variant of this alternative embodiment (not shown) the movable element 
could be a control rod passing through the casing, which control rod 
translates the pivotal movement of the seatback portion 66 of the seat 
assembly 21 via a bell crank lever on the seatback portion 66 to a 
corresponding linear movement, which linear movement is adjustably 
controlled by the locking mechanism according to the invention positioned 
on the seat cushion portion 68 of the seat assembly 21, which seat cushion 
portion 68 constitutes the stationary element. 
Various other embodiments of the present invention also fall within the 
spirit and scope of the present invention, which is limited only by the 
claims presented herewith.