Auxiliary vehicle seat support rail with dynamic seat belt and seat back anchoring

A floor mounted auxiliary support rail of rail for a wide, bench type seat, provides extra load support intermediate the conventional, outboard seat adjuster tracks, as well as providing dynamic anchoring for the seat back and for a traveling seat belt support. A traveling seat belt support is slidably mounted to an auxiliary support rail by a pair of side by side rollers. Beneath the rollers, a pair of locking pins rest below a series of teeth in a rail slot. The rear locking pin is fixed to the seat belt support, while the front locking pin is fixed to an inboard seat back bracket support. The seat back bracket support is pivoted to the head of the forward roller, and the weight of the seat back continually holds the seat back bracket support, as well as the forward roller, down against the upper rail edge, and also holds both pins away from the teeth. A spring pulls the seat belt support back relative to the seat back bracket support, so that the rear roller is held down on the rail edge, as well. In the event of an extraordinary forward force, the seat belt support tips forward about the front roller, pulling the rear roller up against the tension of the spring and driving the rear locking pin into the teeth to anchor the seat belt to the rail and floor. In the event of an extraordinary rearward force, the seat back and its support bracket tip back about the rearward roller, pulling the front roller up against the force of gravity and driving the front locking pin into the teeth to anchor the seat back bracket (and seat back) to the rail and floor.

TECHNICAL FIELD 
This invention relates to vehicle seats in general, and specifically to a 
vehicle seat with an auxiliary support rail that also acts to anchor both 
a movable seat belt support and seat back dynamically to the vehicle in 
the event of extraordinary deceleration or acceleration forces. 
BACKGROUND OF THE INVENTION 
Narrower, so called bucket or individual seats can be adequately supported 
in a vehicle by a single pair of parallel seat tracks, which support the 
seat cushion frame to the floor and allow it to be slidably adjusted back 
and forth. The seat back is pivoted to the seat cushion frame, often by a 
recliner mechanism, which includes lower brackets, one on each side, fixed 
to the seat cushion frame. The seat back is subject to ordinary, everyday 
rearward forces in operation, from the rearward leaning of the seat 
occupants and normal engine acceleration, which the recliner mechanism can 
easily handle. The seat back is also potentially subject to larger, 
extraordinary rearward forces, such as the sudden acceleration of the 
vehicle attendant upon a rear impact. The seat occupant is forced into the 
seat back, which is forced backward about the recliner mechanism. While 
the seat back and recliner mechanisms are made robust enough to hold up, 
the recliner mechanism may deform slightly under such forces, which are 
generally resisted only by strength of the recliner lower bracket's 
mechanical attachment to the seat cushion frame. With individual seats 
having individual occupants, conventional seat tracks and recliner 
attachments are sufficient to handle any expected forces. In the case of 
wider, so called bench seats, which support two or more occupants, 
including center occupants, conventional seat tracks and seat back 
attachment brackets may have to be strengthened, or extra ones provided. 
Center occupant weight, if supported only by two, widely spaced tracks, is 
analogous to a weight sitting at the center of a board supported by only 
two widely spaced saw horses. Likewise, a center occupant forced against 
the seat back in the event of extraordinary acceleration of the vehicle 
stresses the seat back at a point midway between two widely spaced seat 
back brackets. 
Seat belts and their lower attachment points are also subject both to 
ordinary, forwardly acting tension forces, and potentially subject to 
greater, extraordinary tension forces, as in the sudden deceleration 
attendant upon a front impact. A relatively recent trend in vehicle seat 
design is the provision of a lower seat belt attachment point (for buckle, 
or webbing, or both) that moves concurrently with the seat and seat 
cushion, maintaining a consistent relative position., rather than being 
directly fixed to the vehicle body floor. This may be accomplished by 
fixing the belt directly to the seat frame, in which case belt loads are 
indirectly transferred to the vehicle floor through the seat adjuster 
tracks. However, means also exist for transferring belt loads more 
directly to the vehicle body floor, while still maintaining the benefit of 
a moving belt attachment point. Typically, a belt support member is 
attached to the seat, so as to move with it, but a toothed bar pivotally 
anchored to the vehicle floor is also provided below the belt support 
member. The belt support member, in turn, carries a locking pin that 
slides along below the toothed bar. A deformable plastic sheath is used to 
prevent the locking pin from engaging the teeth during normal operation. 
In the event of a stronger than normal pull on the belt, the locking pin 
is pulled up and into the toothed bar, crushing the sheath, and the loads 
are transferred directly to the vehicle floor. Typically, these toothed 
bars are passive except in the event of a collision, and provide no other 
function but the dynamic seat belt anchoring. An example may be seen in co 
assigned U.S. Pat. No. 5,226,697 issued Jul. 13, 1993 to Borlinghaus et 
al., and there are numerous other patents disclosing variations of the 
same basic design. 
SUMMARY OF THE INVENTION 
The subject invention provides all of the desired features noted above, in 
one compact mechanism. In the preferred embodiment disclosed, a wide, 
bench type seat has a cushion frame that is supported at its two outboard 
sides by two widely spaced, conventional adjuster tracks. An equally wide 
seat back is pivoted to the seat cushion frame by a conventional recliner 
mechanism. The recliner mechanism has two widely spaced, outboard lower 
brackets that are bolted directly to the sides of the seat cushion frame 
in such a way as to remain stationary when the seat back is subject to 
normal rearward forces, but to allow a limited degree of backward pivoting 
if the seat back is forced backward with greater force. The invention 
provides extra load support intermediate the widely spaced sides of the 
seat, as well as dynamic anchoring for the seat back, and also provides a 
movable seat belt support that has dynamic anchoring. 
A pair of parallel auxiliary support rails, located inboard of the sides of 
the seat, are fixed to the floor generally below the center occupant 
position. Each rail is a single, solid piece, with an upper straight edge 
and a narrow rectangular slot below cut with a series of locking teeth 
just below the upper edge. Riding on and over each rail upper edge is a 
seat belt support comprised of a pair of inner and outer plates sandwiched 
together around the rail by a pair of side by side pivot pins. Each pin 
journals a cylindrical roller thereon, so that the seat belt support can 
roll back and forth freely on the rollers. A seat belt buckle or belt 
webbing is attached to the top of each seat belt support, above the 
rollers, so that a pull on the belt puts a forward moment on the seat belt 
support, tending to tip it forward about the forward most pivot pin and 
roller. Below the rollers, a locking pin is fixed to the seat belt support 
below the rollers, which normally moves freely in the rail slot, but which 
can engage the locking teeth if and when the belt support tips forwardly. 
A seat back bracket support is attached to the inboard head of each of the 
forward most pivot pins. The seat back also has two extra inboard brackets 
aligned with the two auxiliary rails, each of which is attached rigidly to 
a respective seat back bracket support. Therefore, the weight of the seat 
back, and, indirectly, part of the weight of the seat occupants, is 
transferred through the seat back bracket supports to the rollers. This 
weight is transferred most directly to the forward most rollers, to which 
the seat back brackets are directly attached, so the forward most rollers 
are continually held down against the rail upper edges, at least in the 
absence of extraordinary backward forces on the seat back. However, the 
seat belt supports can still independently tip forward relative to the 
seat back bracket supports about the forward pivot pin-rollers, if pulled 
forward by the belt. Therefore, an extension spring is stretched between 
each seat belt support and the rear of its respective seat back bracket 
support, strong enough to counterbalance ordinary belt forces, and thereby 
keep the rear rollers on the rail edges. Finally, another locking pin is 
fixed to each seat back bracket support, forward of the locking pin on the 
seat belt support. The forward locking pin is also capable of engaging the 
locking teeth if the seat back bracket support is tipped rearward in 
response to an extraordinary rearward force on the seat back. 
In normal operation, as the seat is adjusted fore and aft on the 
conventional, outboard tracks, each auxiliary support mechanism 
concurrently rolls back and forth on the rails. The lower belt attachment 
points maintain a constant position relative to the seat cushion frame, 
and the seat receives extra weight support near the center. In the event 
of an extraordinary forward acceleration of the vehicle, the seat belt 
supports tip forward about the front rollers, independently of the seat 
back bracket supports, stretching the springs. The rear locking pins are 
driven into the locking teeth, and belt loads are anchored directly to the 
vehicle floor. In the event of an extraordinary rearward deceleration of 
the vehicle, the seat back and all of the seat back brackets and the 
bracket supports to which they are fixed are tipped backward. 
Concurrently, the front rollers are lifted from the rail edges and the 
front locking pins are driven into the locking teeth, anchoring the seat 
back directly to the vehicle floor. So, several functions, including self 
compensating belt motion, extra seat support, and front and rear dynamic 
anchoring, are provided by the same structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring first to FIG. 1, the invention is incorporated with a so called 
bench type seat 10, which includes a wide seat cushion frame 12 supported 
on a vehicle body floor 14 by a widely spaced parallel pair of primary, 
outboard seat adjuster tracks 16. The tracks 16 are released by a 
conventional bar 18 to move the seat cushion frame 12 fore and aft. Moving 
along with the seat cushion frame 12 is an equally wide seat back, 
indicated generally at 20. Seat back 20 is comprised of three contiguous U 
shaped sub frames with two outboard legs and two inboard legs, and is thus 
wide enough to accommodate three occupants, including a central occupant. 
The seat back 20 is attached to the cushion frame 12, indirectly, by a 
conventional power recliner mechanism, indicated generally at 22. Recliner 
22 has a long pivot rod 24 that runs cross car through the four lower leg 
ends of the seat back 18. The recliner 22, in turn, is attached to the 
seat cushion frame 12 at the same four points through four seat back 
brackets, two outboard brackets 26 and two inboard brackets 28. The seat 
back 20 is tilted relative to the seat cushion frame 12 to a desired 
reclined position by adjustment of the recliner 22. The operation of the 
subject invention would be the same, however, even if the seat back 20 
were attached directly to the seat cushion frame 12 through the brackets 
26 and 28, without the controlled tilting provided by interposed recliner 
22. The seat back 20 is subject to ordinary backward forces, as indicated 
by the arrows, due to rearward leaning of the seat occupants or normal 
vehicle forward acceleration. It is also potentially subject to 
extraordinary, higher than normal rearward forces, as in the event of a 
rear impact. Such forces could bend or deform the seat back 20, if high 
enough. Alternately, if a suitable pivot axis were available, the seat 
back 20 could rotate or tip slightly backward relative to the seat cushion 
12. Or, further deformation could occur after the rotation stopped. Here, 
such a pivot axis is provided about which the seat back 20 can tip or 
rotate in a controlled, limited fashion, in preference to the other 
potential axis of the recliner pivot rod 24. Specifically, the outboard 
seat back brackets 26 are each attached to the sides of the seat cushion 
12 with two bolts, a rear bolt 30 that runs through a close fitting slot, 
and a front bolt 32 that runs through an arcuate slot 34 arrayed about the 
center of rear bolt 30. Each front bolt 32 is tightened down over the 
edges of arcuate slot 34 tightly enough to resist any rotation of the 
outboard seat back bracket 26 in response to normal forces on seat back 
20, but can slip, in response to higher forces, to allow rotation about 
the axis of the aligned rear bolts 30, at least to the extent allowed by 
the length of the slots 34. The subject invention allows the other, 
inboard seat back brackets 28 to follow the rotation of the outboard seat 
tracks 26, in a manner described in detail below. The seat 10 also 
incorporates several seat belts, not illustrated, which have at least two 
lower attachment points, indicated by the forwardly pointing arrows in 
FIG. 1. These belt attachment points may each comprise one or more buckles 
or webbing as needed to provide the belt configuration and number desired. 
In any event, the belts would be subject to ordinary, tension forces, 
acting in the direction shown, due simply to occupant forward leading or 
ordinary deceleration forces, such as braking. As with the seat back 20, 
the belts would also be potentially subject to extraordinary tension 
forces due to higher than normal deceleration, as in the case of a front 
impact. The invention also dynamically anchors the belt attachments, in 
the event of higher than normal deceleration. 
Referring next to FIGS. 1, 2 and 3, a preferred embodiment of the combined 
auxiliary support rail and dynamic seat belt and seat back anchoring 
mechanism of the subject invention, of which two are incorporated in seat 
10, is indicated generally at 36. Although basically identical, the two 
mechanisms 36 are oriented in mirror image about the centerline of the 
vehicle floor 14, so that there is a specific right and left mechanism 36, 
as seen in FIG. 1. A detailed description is provided for the right 
mechanism 36 (right from the perspective of a seat occupant) in the 
Figures following FIG. 1, which applies equally well to each. Each 
mechanism 36 consists of three basic parts, a support rail, indicated 
generally at 36 , a seat belt support, indicated generally at 40, and an 
inboard seat back bracket support, indicated generally at 42, one for each 
inboard seat back bracket 28. The stationary base or foundations of the 
mechanisms 36 are the stamped steel support rails 38. Two rails 38 are 
bolted to the vehicle floor 14 below the seat cushion 12, parallel to one 
another and to the primary seat tracks 16, and located just outboard of 
the inboard seat back brackets 28. Each rail 38 has a straight, 
substantially horizontal upper edge 44, comparable in length to the 
primary adjuster tracks 16, below which a narrow rectangular slot 46 runs 
for most of its length. The upper edge of each slot 46 is formed with a 
regular series of locking teeth 48. The seat back bracket support 42 is a 
generally triangular stamped steel plate, which has a robust locking pin 
50 rigidly attached to it's lower forward corner, extending outboard. 
Three smaller seat back bracket studs 52 are rigidly attached along it's 
lower edge, extending inboard, to which an inboard seat back bracket 28 is 
ultimately fixed. A stop tab 54 is lanced near the lower edge, for a 
purpose described below. At the upper corner of the triangle, an offset 
stamped boss 56 is formed. The seat belt support 40 consists basically of 
two generally diamond shaped stamped steel plates 58, which are sandwiched 
around the rail 38 to slide back and forth thereon. Specifically, a 
longer, front pivot pin 60 and a shorter, rear pivot pin 62, each of which 
is surrounded by a free turning roller 64 and 66 respectively, along with 
a rear locking pin 68, serve to hold both the pair of plates 58 and the 
seat back bracket support 42 together. First, the rear locking pin 68 is 
captured between the lower corners of the two plates 58, running through 
the rail slot 46, and spun down on both ends. This loosely holds the two 
plates 58 together on rail 38. Next, the rear pivot pin 62 (with roller 66 
)is captured between the two plates 58, just above the rail edge 44, and 
spun down at both ends. Then, the longer, front pivot pin 60, which has a 
wider head at its outer end, is inserted narrow end first through the seat 
back bracket support boss 56, through the aligned plates 58 and through 
the front roller 64 (which is held between the plates 58). The narrow end 
of the front pin 60 is then spun down, at which point both the plates 58 
are captured slidably on the rail 38, with the rollers 64 and 66 located 
above the upper rail edge 44, and with the two locking pins 50 and 68 
located in the rail slot 46. Finally, a stretched coil extension spring 70 
is hooked between the attached plates 58, from a point near their upper 
ends, to the rear of the seat back bracket support 42, completing the 
mechanism 36, as seen in FIG. 3. Stretched spring 70 tends to pull the 
seat back bracket support 42 and rotate it up about the wider head of the 
front pivot pin 60, but the degree of relative rotation is limited, at 
least prior to installation of the mechanism 36, by stop tab 54 hitting 
the edge of the plates 58. The actual function of spring 70 is not related 
to the assembly of mechanism 36, but to its post installation operation, 
described next. 
Referring next to FIGS. 1, 4 and 5, the normal operation of seat 10 and 
mechanism 36 is illustrated. Each mechanism 36 is installed by fixing a 
respective inboard seat back bracket 28 to the three short studs 58 on a 
support 42, which are spun down over the outer surface of the bracket 28. 
Then, when seat 10 and the primary seat adjuster tracks 16 are installed 
to the vehicle, the rails 38 are also bolted stationary to the vehicle 
floor 14. Belt webbing and/or buckles are fixed to the top corners of the 
seat belt supports 40. When the seat cushion frame 12 is supporting 
occupants, especially in the center, it is stressed downwardly, and more 
so toward the center. There is no direct connection between the seat 
cushion frame 12 and the mechanisms 36 as illustrated, since the cushion 
frame 12 is slotted to clear the mechanisms 36. However, the cushion frame 
12 could be designed to bow down enough, under normal loading, to contact 
the seat back bracket supports 42, and thereby force the rollers 64 and 66 
against the rail upper edges 44. That load would be seen most strongly by 
the front pivot pins 60 and rollers 64, since they are directly connected 
to the bracket supports 42. Likewise, the weight of the seat back 20 
itself, plus the portion of the occupant weight acting downwardly through 
seat back 20, will act most directly on and through the front rollers 64. 
These normal downward weight loads, indicated by the arrow Fsn in FIG. 4, 
act to keep the front rollers 64 against the rail upper edges 44, in the 
absence of any extraordinary forces tending to lift them up and away. 
Likewise, the upper corners of the seat belt supports 40 are subject to 
normal belt forces, indicated by the arrows labeled Fbn. Because the 
bracket support 42 is attached to the seat belt support 40 at a single 
pivot point, that being the head of the front pivot pin 60, the normal 
belt forces shown at Fbn would be capable of applying a forward moment to 
the belt support 40 and rotating it relative to the stationary bracket 
support 42 about the front pin 60, or counterclockwise as seen in FIG. 4. 
This could lift the rear roller and pivot pin 66-62, at least in the 
absence of a countervailing rearward moment tending to rotate the seat 
belt support 40 in the opposite direction, clockwise in FIG. 4. This is 
provided by the stretched springs 70, which provide enough rear force to 
counteract the forward pulling, normal seat belt forces, and thereby keep 
the rear rollers 66 down on the rail upper edges 44. Since the rollers 64 
and 66 stay on the rail upper edges 44, the locking pins 50 and 68 are 
kept out of the locking teeth 48 with no need for a crushable plastic 
sheath. Therefore, during normal seat operation, when the primary adjuster 
tracks 16 are released to let seat 10 move back and forth, both mechanisms 
move passively back (FIG. 4) or forward (FIG. 5) in lock step with seat 
10. Both rollers 64 and 66 are kept solidly on the rail upper edges 44, 
and extra weight support is provided to the center of seat cushion frame 
12. Extra weight support alone is an advantage, since the auxiliary rails 
38 are much more compact and less costly than conventional seat adjuster 
tracks 16. The mechanisms 36 also provide dynamic anchoring, in response 
to extraordinary forces, as described next. 
Referring next to FIGS. 6 and 7, the response of the mechanisms 36 
extraordinary deceleration is illustrated. FIG. 6 shows the normal 
position, with both rollers 64 and 66 firmly on the rail upper edges 44. 
Both of the locking pins 50 and 68 are thereby held out of and away from 
the locking teeth 48, with no need for an insulating plastic sheath to 
prevent engagement. FIG. 7 show the response of mechanism 36 to a greater 
than normal tension force acting at the top of the seat belt support 40, 
shown at the arrow labeled Fbe. Such a force, resulting from a frontal 
collision or the equivalent, would put a forward moment on the seat belt 
supports 40 strong enough to overcome the force of the springs 70. Most of 
the downward force on the front rollers 64 would still be present, more 
than enough to keep the front rollers 64 solidly down against the rail 
upper edges 44 and to keep the seat back bracket supports 42 from rotating 
relative to the rail 38. The rear rollers 66 and rear pivot pins 62 can 
lift up from the rail edge 44, however, due to the forward moment 
described, rotating counterclockwise about the pivot axis provided by the 
front rollers and pivot pins 64 and 60. Concurrently, the rear locking 
pins 68 are rotated up and into the locking teeth 48, providing a direct 
belt load transfer into the rails 38 to anchor the belts directly to the 
vehicle floor 14. As soon as normal belt forces return, the springs 70 
return the rear rollers 66 to the rail upper edges 44, and the rear 
locking pins 68 move back down and out of the locking teeth 46. 
Referring next to FIGS. 1 and 8, the response of mechanisms 36 to 
extraordinary acceleration is illustrated. Again, in the event of a rear 
collision or the like, higher than normal forces are put on seat back 20, 
in the direction of the arrows in FIG. 1. This causes a rear moment on 
seat back 20, transferred ultimately to the outboard seat back brackets 
26. As noted above, the higher than normal rear moment is enough to 
overcome the tightening force on the heads of the front attachment bolts 
32. Rearward pivoting of the seat back 20 and outboard seat back brackets 
26 occurs about the pivot axis provided by the rear attachment bolts 30 as 
the front bolts 32 slip through the arcuate slots 34. Concurrently, the 
same forces acting on the set back 20 would be transferred to the two 
inboard seat back brackets 28. A moment would thereby be applied to the 
seat back brackets supports 42 at the endmost attachment studs 52, as 
shown by the oppositely directed arrows in FIG. 8. This moment would be 
sufficient to overcome the normal downward forces on the front rollers 64 
and pivot pins 60, as the inboard brackets 28 and their respective 
supports 42 rotated clockwise, matching the limited backward rotation of 
the seat back 20 and outboard brackets 26. The front rollers 64 and pivot 
pins 60 are thereby lifted from the rail upper edges 44. The rear rollers 
66 are shown remaining against the rail edges 44, as there are no 
particular forces acting to lift them, but they do not themselves provide 
the axis of rearward rotation for the seat bracket supports 42, as do the 
front pivot pins 60 for the seat belt supports 40. That axis is provided 
by the outboard bracket rear attachment bolts 30. Simultaneously, the 
front locking pins 50 are lifted up to engage the locking teeth 48. The 
rotation of the inboard brackets 28 is thereby stopped, and the forces are 
transferred directly to the rail 38 and the floor 14. Simultaneously, the 
rotation of the outboard brackets 26 is stopped by the front attachment 
bolts 32 bottoming out in the arcuate slots 34, and forces there are 
transferred to the floor 14 through the primary seat adjuster tracks 16. 
So, four fairly evenly spaced dynamic anchoring points are provided to 
resist backward rotation of the seat back 20, rather than just two widely 
spaced points at the primary seat tracks 16. 
In conclusion, a number of functions are provided by the mechanisms 36. 
Extra weight bearing support is provided for the entire wide seat 10 near 
the center, without the use of one or more additional seat adjuster tracks 
16, which would be much wider and heavier than the relatively thin rail 
18. A self compensating lower belt attachment point, as well as dynamic 
seat belt anchoring, is provided by the belt supports 40 in cooperation 
with the weight bearing seat back bracket supports 42. Conventional seat 
belt anchoring bars, running parallel to the rail, are not needed. Dynamic 
anchoring for the wide seat back 20 is provided for the inboard seat back 
brackets 28 and their respective supports 42, in cooperation with the 
slotted outboard seat back brackets 26, a function that would not be 
provided even with the addition of extra conventional seat adjuster tracks 
and anchoring bars. 
Variations could be made in the preferred embodiment disclosed. The support 
rail could be formed as a more or less solid piece, such as a forging, 
without the long through slot 46. Such an alternate rail design could have 
wide upper edges with a series of downwardly opening locking teeth arrayed 
beneath the upper edges, formed into an overhanging solid shelf running 
beside the upper edge. Such a construction would be significantly thicker 
and heavier than the slotted, single thickness rail 38 disclosed. A single 
piece seat belt support could ride along the wider upper edges of such a 
solid, non slotted rail, rather than the two plate, bifurcated seat belt 
support 40 disclosed. Such a one piece seat belt support would have to be 
kept "on track" by other means, as, for example, by the use of a pair of 
wider, side flanged rollers fitted down over the wider upper edges, 
similar to train wheels on train tracks. An inboard seat back bracket 
would be pivoted to one end of the front roller, on that side of the seat 
belt support that had access beneath the locking teeth. Both locking pins 
in such a design would be fixed only at one of their ends to the seat belt 
support and seat back bracket support respectively, cantilevered beneath 
the overhanging toothed shelf. This alternate, heavier design would 
provide all of the support and anchoring benefits of the disclosed 
embodiment, and could likely be used where very heavy load and force 
support was desired. The embodiment disclosed, with the thinner, slotted 
rail 38, and bifurcated, double plates 58, has assembly advantages, 
however. The two plates 58 and the rear locking pin 58 sandwiched between 
them and resting in slot 46, cooperate, along with the pivot pins 60 and 
62 also sandwiched between the plates 58, to capture the plates 58 to the 
rail 38. This helps later installation, since the rail 38, seat belt 
support 40, and inboard seat bracket support 42 are all captured together, 
rather than loose parts. Other resilient means could be provided to create 
a continual rearward moment on the seat belt support 40, to keep the rear 
roller 66 seated on the rail edge 44. A torsion spring wrapped around the 
head or front pin 60 could continually act to rotate seat belt support 40 
backward relative to the seat back bracket support 42. Or, a compression 
spring could push the rear roller 66 down relative to the seat back 
bracket support 42. The tension spring 70 simply hooked between the two 
supports 40a and 42 is simple and easy to install, however. Therefore, it 
will be understood that it is not intended to limit the invention to just 
the embodiment disclosed.