Patent Publication Number: US-6220809-B1

Title: Vehicle restraint and improvements

Description:
This is a Divisional of U.S. Ser. No. 09/354,357 U.S. Pat. No. 6,074,157, filed Jul. 14, 1999 which is a Divisional of U.S. Ser. No. 08/697,937 U.S. Pat. No. 6,010,297, filed Sep. 3, 1996. 
    
    
     FIELD OF THE INVENTION 
     The invention is directed generally to vehicle restraints, and more particularly to improving the ability for vehicle restraints to prevent vehicles from uncontrolled separation from loading docks. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Vehicle restraints are well known in the art, and serve the vital safety function of preventing trucks and the like parked at a loading dock from separating from the dock during the loading or unloading of the vehicle. In the absence of a vehicle restraint, or if a vehicle restraint malfunctions, the vehicle may uncontrollably separate from the dock, leaving a gap between the vehicle and the dock and/or dockleveler disposed therein. As used herein “uncontrolled” separation refers to the situation where a truck separates from the dock at a time when such separation is undesired—such as when loading or unloading of the truck is occurring and/or when a vehicle restraint is engaged. For an uncontrolled separation, a fork truck operator (or other personnel or equipment) either approaching the rear of the truck or leaving the rear of the truck could fail to realize the presence of the gap with dire consequences—the worst being the fork truck falling from the loading dock or the truck to the driveway below. Indeed, several such accidents led, in part, to the innovation of the vehicle restraint itself. 
     While vehicle restraints fall into several general categories, the most prevalent category is ICC bar restraints. Such restraints are typically mounted on or adjacent to the dock face and include a hook or restraining member which engages the rear impact guard or “ICC bar” of the vehicle to prevent uncontrolled separation. The National Highway Transportation Safety Administration (NHTSA) recently promulgated new regulations for ICC bars, to take effect in 1998 (although truck manufacturers are already beginning to provide ICC bars that conform to the new regulations). Under these regulations, the ICC bars must be at least 4 inches in height, and meet other requirements for strength and deflection response to applied forces. For an ICC bar restraint to effectively perform the important function of preventing uncontrolled separation, it must be capable of restraining ICC bars conforming to the new standards. 
     One style of ICC bar restraint is that disclosed in U.S. Pat. No. 4,865,508 to Carlson, and commercially embodied in a vehicle restraint sold by the Kelley Company, Inc. of Milwaukee, Wis. under the model name “Star.” A Star-style restraint is depicted in FIGS. 1-9 of the attached drawings. In conducting tests of vehicle restraints in light of the new NHTSA standards, we have determined that the present design of a Star-style restraint makes the restraint susceptible to the dangerous condition of allowing a vehicle with what appears to be a properly restrained ICC bar to pull away and separate from the loading dock under certain commonly-occurring circumstances. As will be described in greater detail in the specification to follow, we have determined that the design of a Star-style unit allows the restraining member to be forced downward by a departing ICC bar to a position where it fails to restrain the ICC bar and the vehicle can drive or otherwise move away from the loading dock. 
     Accordingly, an object of the present invention is to provide improvements and modifications to a Star-style unit and other similar restraints that prevent such restraint failure. Beyond that, however, it is also an object of the present invention to generally provide safer vehicle restraints that maintain engagement with a vehicle ICC bar, particularly during pull-aways. It is a further object of the invention to provide this enhanced safety to vehicle restraints without otherwise impeding the normal operation of such restraints. It should be noted that while the inventions disclosed herein may be useful in enhancing the operation of given vehicle restraints, some restraints will not require use of the invention as other features of those restraints provide the desired functionality. Further still, certain restraints may have design characteristics that prevent incorporation of the inventive concepts of this application while still allowing the restraint to practically service the varied configurations of ICC bars and trailers. 
     In accordance with these and other objects of the invention, there is provided improved components for vehicle restraints as well as improved restraints, which are intended to eliminate or minimize the causes of uncontrolled separation attributable to Star-style and similar units. In addition to providing improved restraint components and restraints that avoid these causes, there is also provided specific improvements to Star-style units or similar restraints, the improvements being intended to prevent or minimize the possibility for uncontrolled separation of a parked, restrained vehicle from a loading dock. 
     The improved restraints, restraint components and the specific improvements to the Star-style restraints fall into two general categories. In the first category, improvements to the design of the barrier portion or head of the restraining member are provided. The barrier portion or head is the portion of the restraining member behind which the ICC bar is intended to be captured. The new restraining member designs and the Star-style head improvements prevent what is believed to be the primary factors contributing to Star-style units being forced downward and out of restraining engagement by a departing ICC bar. The other broad category of restraints, restraint components and specific improvements to the Star-style restraint are directed to locking the restraining member of a restraint into a given vertical position for a pull away by the parked vehicle. The lock does not impede normal operation of the restraint, but is only activated during a pull away to prevent failure of the restraint. 
     The embodiments of the invention will be described herein in reference to the appended drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAGS 
     FIGS. 1-9 are a series of views of the prior art Kelley Star restraint, and illustrating what is believed to be the mechanisms leading to the observed failure of the Star for certain pull away conditions; 
     FIG. 10 is a front elevation of an improved head configuration for the prior art restraint, according to one embodiment of the invention; 
     FIG. 11 is a perspective view of an improved head configuration for the prior art restraint, according to an alternative embodiment of the invention; 
     FIG. 12 is a front elevation of an improved head configuration for the prior art restraint, according to a further alternative embodiment of the invention; 
     FIG. 13 is a perspective view of an improved head configuration for the prior art restraint, according to a further alternative embodiment of the invention; 
     FIG. 14 is a side elevation of an improved head configuration for the prior art restraint, according to a further alternative embodiment of the invention; 
     FIG. 15 is a front elevation of an improved head configuration for the prior art restraint, according to a further alternative embodiment of the invention; 
     FIG. 16 is a side elevation of an improved head configuration for the prior art restraint, according to a further alternative embodiment of the invention; 
     FIG. 17 is a rear elevation of the improved head configuration of FIG. 16; 
     FIG. 18 is a front operational elevation of the prior art restraint and including an attachable member according to an embodiment of the invention; 
     FIG. 19 is a section view showing the prior art restraint and attachable member of FIG. 18; 
     FIG. 20 is a elevation of the attachable member of FIG. 18; 
     FIG. 21 is a front elevation of the prior art restraint, and showing the improvement of a locking member according to an embodiment of the invention; 
     FIG. 22 is a top plan view of the prior art restraint, and the improvement of the locking member of FIG. 21; 
     FIG. 23 is a section view of the improved restraint of FIG. 21 with the locking device of the invention engaged; 
     FIG. 24 is a section view of the improved restraint of FIG. 21 with the locking device disengaged; 
     FIG. 25 is a section view of the prior art restraint, and showing the improvement of a locking member according to an alternative embodiment of the invention; 
     FIG. 26 is a further section view, subsequent in time to the view of FIG. 25; and 
     FIG. 27 is a close-up section of the locking member of FIG.  25 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as are included within the scope and spirit of the invention as defined by the appended claims. 
     The Star-style unit that we believe to be susceptible to allowing uncontrolled separation of a restrained vehicle from a loading dock is depicted in FIGS. 1-9, which also show the mechanisms that we believe allow the uncontrolled separation. As seen in FIG. 1, the restraint  10  is adapted to be mounted adjacent (in this case on) the face F of a loading dock for selectively restraining the ICC bar (B) of a vehicle (not shown) parked at the loading dock. To restrain the bar B, the restaint  10  includes a restraining member  20  which moves substantially vertically relative to the dock face F, in this case between a lowered, stored position shown in FIG. 1 and a restraining position in FIG.  2 . The restraining member includes a shank portion  21 , which in the case of the Star-style restraint is a cylindrical member, and a barrier or head portion  22 , which in the Star-style restraint is part circular, and includes an upper curved surface  23 . To guide the restraining member  20  in its substantially vertical path relative to the dock face F, the restraining member  20  also includes a first end  25  which in this case forms a follower that engages a slightly curved track  30  mounted to a frame  35  that is in turn mounted on the dock face F. Despite the presence of the slightly curved track  30 , the restraining member nonetheless moves in a substantially vertical path. As is seen most clearly in FIG. 3, the movement of the restraining member is nearly vertical between the lowered, stored position and the restraint position, with the barrier or head  22  varying only slightly from a vertical line. Further, when the movement of the restraining member is viewed from the side (depicted by the arrow “A” in FIG. 3) its motion is seen to be purely vertical. 
     We are presently aware of two mechanisms by which the Star-style unit is moved from the lowered position of FIG. 1 to the restraining position of FIG.  2 . In both versions, a gas spring powers this movement, with the restraining member being held in a lowered, stored position against the bias of the gas spring. In the manual version, manual release of a latch allows the restraining member to rise to the restraining position. The gas spring acts on an actuating arm ( 40  in FIGS. 1 and 2) which is connected to the restraining member to move the restraining member upwardly. A manual downward force must be applied to the restraining member to move it back to the stored position. In the powered version of the Star-style unit, a separate, hydraulic cylinder is actuated to release the actuating arm  40  from the stored position, allowing the upward bias of the gas spring  45  to move the restraining member  20  in its substantially vertical path. Reverse actuation of the hydraulic cylinder returns actuating arm  40  and the restraining member  20  to the stored position, where it is then maintained. The upward bias of the restraining member  20 , provided by the gas spring, not only raises the restraining member  20 , but also allows the restraining member to “float” up and down with the truck as it is loaded and unloaded (the weight variances causing the vehicle&#39;s suspension to move the vehicle up and down) to maintain the restraining member in a restraining engagement with the ICC bar B. It will thus be appreciated that as used herein the term “restraining position” is not a single position in free space of the restraining member, but rather is a range of spatial positions in which the upwardly-biased restraining member  20  is in restraining engagement with the bar B, such that the bar B is in contact with the shank  21  and is thus confined behind the barrier or head  22  to prevent the bar from moving outward away from the dock. Toward that end, the barrier or head  22  is disposed substantially parallel to the dock face F, as is seen most clearly in the side section of FIG.  8 . 
     As discussed above, we have determined that the Star-type restraint is susceptible to allowing what appears to be a properly restrained ICC bar to be pulled away from the dock face by movement of the vehicle away from the dock. The mechanisms which we believe contribute to this failure are illustrated in FIGS. 4-9. As shown in the top view of FIG. 4, portions  50 ,  51  of the ICC bar B that are disposed laterally of the head  22  will tend to deform and “wrap around” the head  22  when the restrained bar B pulls away from the dock face. Depending on the orientation of the ICC bar when pull away occurs, one or both lateral portions  50 ,  51  will tend to wrap around. Both portions are shown wrapping around in FIG.  4 . Of course, the ICC bar B will deform more for a greater exerted pull-out force, and less for smaller forces. Wrap around will occur at forces above some predetermined magnitude. Assuming a pull out force above that predetermined magnitude, the wrap around depicted in FIG. 4, and also seen in the section view of FIG. 5 would occur. This wrap around by the lateral portions  50 ,  51  of the ICC bar B causes the head  22  of the restraining member to be pinched between one or both of the two arms  50 ,  51 , particularly in the curved upper surface  23  of the head  22 . This pinching of the head  22  is depicted by the sets of small arrows  55 ,  56  in the front elevation view of FIG.  6 . The pinching of the curved surface  23  of the head  22  causes a camming action between at least one of the lateral portions  50 ,  51  (and perhaps both) and the curved surface, in which the lateral portion(s) ride up and around the curved surface, as depicted by the larger arrows  57 ,  58  in FIG.  6 . Since the ICC bar is substantially fixed in its vertical position, and is incapable of any substantial movement upward, the result of this camming action is a downward movement of the head  22  (as depicted by arrow  60 ) and thus the restraining member  20 . As the vehicle and attached ICC bar B continue to move away from the dock, this camming action continues until the restraining member  20  is moved downward a large enough distance to allow the ICC bar to no longer be restrained. We believe this camming action to be the primary cause of the failure of the Star-style restraint for pull aways having a force above a predetermined magnitude. 
     A further, and we believe secondary, mechanism is depicted in the views of FIGS. 7-9. As seen in FIG. 7, the track  30  includes a rear surface  31  and a front surface  32 , while the follower  25  includes surfaces  26  and  27  which face the surfaces  31 , 32  on the track  30 . During normal operation of the restraint, the surfaces  26  and  27  are desired to, and tend to remain spaced from the surfaces  31 ,  32 . For a pull away, however, the outward force exerted by the ICC bar B on the head  22  tends to move the entire restraining member  20 , and the follower  25  in an outward direction. As the camming action referred to above occurs, the head  22  of the restraining member tends to be moved downward. As a result, and as seen most clearly in FIG. 9, this causes portions of the surfaces  26  and  27  to frictionally engage the surfaces  31  and  32 , respectively. As a result, the restraining member  20  tends to become canted, with the head end  22  moving downward under the camming forces exerted thereon by the ICC bar, and the first end adjacent the follower tending to, at least temporarily, maintain its vertical distance above the driveway. This canted orientation causes a second camming action to occur between the canted tip of the head  22  and the vertical front surface S. Continued movement of the ICC bar B away from the dock face thus causes an additional downward force to be exerted on restraining member  20 . We also believe that this secondary camming action may be exacerbated by a slanting of the ICC bar such that its upper surface moves further away from the dock than its lower surface, as seen in phantom in FIG.  9 . This slanting is caused by a yielding of the vertical uprights to which the ICC bar is attached (labeled “U” in FIG.  1 ). As a dockward force is exerted by the restraint on the ICC bar during pull away, these uprights may yield backward (toward the dock), causing the normally squared ICC bar to slant as in FIG. 9 phantom. This enhances the secondary camming effect. Eventually (actually in a matter of milliseconds) the downward forces exerted on the restraining member by at least one of the two camming actions overcome the frictional force between the follower  25  and the track  30 , and the entire restraining member moves downward. As a matter of fact, in the Star-style restraint failures we have observed, the head end of the restraining member is first canted downward by the departing ICC bar B, and then the entire restraining member is thrown toward the lowest point of its range of travel, thus leaving the ICC bar B totally unimpeded and able to continue away from the dock face. 
     We have determined that the Star-style restraint can be improved by modifying the design of the head such that one or both of the camming actions referred to above, and which force the restraining member down, are either eliminated or counteracted. Several embodiments of improved heads for the Star-style restraint and which may also (although not necessarily) be applicable to other types of restraints, are depicted in FIGS. 10-17. The improved head  122  in FIG. 10 includes a pair of parallel lateral surfaces  123  and  124  disposed about a vertical centerline (CL) of the head  122 , the centerline being in a plane parallel to the dock face. Since the lateral surfaces  123 ,  124  are vertical, a pulling away ICC bar will not be able to cam up and around the curved upper surface of the head  122  during a pull away. Rather, one or both of the portions  50 ,  51  of the ICC bar disposed laterally of the head  122 , and which wrap there around, will catch on the vertical surfaces, thereby maintaining the restraining member to which the head  122  is attached in a restraining position with respect to the ICC bar B. This effect could be enhanced by making the lateral surfaces  123 ,  124  concave, as depicted in broken lines in FIG.  10 . This effect could also be enhanced by roughening the lateral surfaces  123 ,  124  to increase the frictional engagement between those surfaces and the lateral portions  50 ,  51  of a wrapping around ICC bar. An exemplary embodiment of such roughening for surfaces  123 ,  124  is shown in FIG. 11, in which the surfaces are toothed. It will be appreciated that the lateral surfaces  123 ,  124  will not always be vertical as in FIG. 11 given that the head of the Star-style unit sweeps through a minimally curvilinear path as it moves to the engaging position. Even so, the surfaces are vertical in the head position of FIG.  10 . Movement of the head  122  to a different restraining position would cause one of the lateral surfaces to diverge upwardly and outwardly from a vertical line in a plane parallel to the dock face, as will be addressed in the embodiment of FIGS. 12,  13  and  15 . 
     Another improved head  222  is shown in FIG.  12 . Instead of having parallel lateral surfaces as in the previous embodiments, this embodiment includes at least one surface disposed laterally of a centerline CL and forming an acute angle therewith. Indeed, this embodiment includes a pair of lateral surfaces  223 ,  224  disposed in an upwardly-diverging relation relative to the centerline. Because of the upwardly-diverging relation of the surfaces  223 ,  224 , a departing ICC bar wherein lateral portions  50 ,  51  wrap around the head  222  would actually exert a camming action on the head  222  tending to move it (and thus the restraining member to which the head  222  is attached) upward into tighter engagement with the ICC bar B, thus preventing the pull away. This effect could also be enhanced by making the lateral surfaces  223 ,  224  concave, as is depicted in broken lines in FIG.  12 . In addition, the lateral surfaces could be roughened to increase the frictional engagement between the lateral surfaces  223 ,  224  and the lateral portions  50 ,  51  of the ICC bar B as they wrap around the head  222  during a pull away. An exemplary embodiment of such roughening for surfaces  223 ,  224  is shown in FIG. 13, in which the surfaces are toothed. Again, the slightly curvilinear motion of the head portions  122 ,  222  would cause the lateral surfaces  223 ,  224 , as well as surfaces  123 ,  124  (FIGS. 10 and 11) to take on slightly different orientations in addition to those shown in FIGS. 10 and 13 if ICC bars of different heights above the driveway are used. The overall effect of the surfaces preventing downward movement of the hook for wraparound resulting from pull away would be the same. 
     This same concept is also applicable to a head having a rounded upper surface as in a Star-style restraint, and as shown in FIG.  15 . The head  322  in FIG. 15 also includes a pair of lateral surfaces  323 ,  324  disposed in an upwardly-diverging relation. Head  322  also includes a rounded top surface  325  that is continuous with the lateral surfaces  323 ,  324 . The rounded top surface of the head  322  includes a centerpoint C and radius R. So long as the head  322  has a total height such that the centerpoint C is always above the horizontal centerline CL of the ICC bar B, any downward camming action exerted on the head  332  by the curved upper surface  325  will be counteracted by an upward camming action exerted on the head  322  by the lateral surfaces  323 ,  324  as described above. 
     According to an alternative embodiment, the head of the Star-style restraint may be improved by providing a projection on the head that extends toward the dock face, and which either traps or engages the ICC bar B to prevent downward movement of the restraining member relative to the ICC bar. One example of such a projection is seen in FIG. 14, in which an improved head  422  includes a projection toward the dock face in that at least a portion of the inner surface  440  of the head portion forms an acute angle with the shank  421  of the restraining member. For a pull away by the ICC bar B, the bar B would get pulled under the projection  440 , thus preventing the ICC bar B from camming upward on the outer, lateral surfaces of the head  422 . Preferably, this angling of the head would be used in combination with the head design shown in FIGS. 10-13. Further, it is desirable for the head  422  to have an overall height greater than the height of the ICC bar. 
     Alternatively, a projection like that shown in FIGS. 16 and 17 could be used. As seen in those figures, the head  522  is modified to include a projection  540 . The projection  540  is preferably spaced from the shank  521  by a distance greater than the height of the ICC bar B. Accordingly, as the bar B attempts to pull away, it will be trapped beneath the projection  540 , thus causing the projection to catch on the ICC bar B if the restraining member  20  is forced downward. The view of FIG. 16 shows the ICC bar already moved away from the dock during a pull away. During normal operation, the ICC bar will typically be disposed closer to the dock face, and not under the projection  540 . The section view of FIG. 17 shows the profile of the projection  540 . In this embodiment, it includes two angled surfaces  541 ,  542 . The surfaces are angled to take into account the slight rotation of the head  522  as the restraining member traces its slightly curvilinear path of movement, while continuing to maintain proper spacing for ICC bar clearance during normal operation. 
     A related improvement to the Star-style restraint would be to add an attachable member to the restraining member which provides the projection of the previous embodiments. Such an attachable member is shown in FIGS. 18-20. The attachable member  80  would be attached to a conventional Star-style restraint  10 , as in FIG.  18 . Preferably, and as seen more clearly in FIG. 19, the attachable member is adapted to be disposed about the shank  21  of the restraining member  25 . The member  80  includes a projection  81  formed as a part thereof which performs a similar function to the projections described above. Preferably, the attachable member  80  would be freely rotatable about the shank  21 , and would include a counterweight  82  at the end opposite the projection  81 . The counterweight ensures that the projection  81  of the attachable member always maintains a vertical orientation for all positions of the restraining member to maintain proper spacing for ICC bar clearance during normal operation, without the need for the angled surfaces like  541 ,  542  shown in FIG.  17 . To make the attachable member retrofittable to existing Star-style units, it could be formed of two pieces  85 ,  86 , and be joined together by bolts  87  once in place on the shank  21 . 
     It should be noted that the improvements related to the head portion of the Star-style restraint are not limited to that specific restraint. Rather, they may also generally applicable to other restraining members that include a shank portion and a barrier portion operatively coupled thereto, the restraining member being disposed substantially horizontally and the barrier portion being disposed substantially vertically when the restraining member is in the operative position. The term “operatively coupled” in regard to the shank and the barrier is intended to describe not only restraining members in which the barrier is fixed to the shank as in the Star-style unit, but also to other embodiments, such as where the barrier is capable of reciprocating between a position wherein it extends above the shank to form a restraining member, and a position wherein it is stored below or even inside a horizontally-extending surface forming the “shank”. In such restraints with a vertical barrier, the ICC bar may also have a tendency to wrap around the barrier portion for a pull away. The structures of angled lateral surfaces and/or projections from the barrier portion toward the dock face to prevent downward movement of the restraining member for pull away may thus both be applicable to this broader category of restraints. However, it is also true that such restraints may already incorporate features that prevent or minimize uncontrolled separation, thus minimizing or eliminating the advantage of using the present invention. In addition, design aspects of such restraints may make incorporation of the present invention impracticable, particularly in light of the wide variety of trailer and ICC bar configurations. 
     Returning to the Star-style restraint, an alternative solution to modifying the head to prevent downward forces being exerted on the restraining member is to lock the restraining member in its vertical position above the driveway for a pull away. As will be appreciated by one of skill in the art, however, it is undesirable to lock the restraining member in such a vertical position at all times when the ICC bar is restrained during normal operation, since this does not provide for float of the restraining member with the vehicle as it is loaded and unloaded. FIGS. 21-27 depict two embodiments of improvements to the Star-style restraint that provides free floating of the restraining member for normal operation of the restraint, but that also locks the restraining member in a vertical position for a pull away. 
     In the embodiment shown in FIGS. 21-24 a locking device in the form of toothed projections  600  formed in the track  30 , and a pawl member  610  (see FIGS.  23  and  24 ), prevents downward movement of the ICC bar for a pull away, but also provides for “floating” operation of the restraining member for normal conditions. The toothed projections  600  could also be a separate piece or pieces attached adjacent the track  30 . As seen in FIGS. 23 and 24, the pawl  610  is preferably carried adjacent the restraining member—in this case on the actuating arm  40  associated with the restraining member  20 —and is capable of reciprocating movement between a position wherein the pawl  610  is engaged with a toothed projection  600  on the track  30  (FIG.  23 ), and a position wherein it is disengaged from a toothed projection  600  (FIG.  24 ). In the engaged position, the pawl  610  prevents the restraining member from moving downward relative to the track  30 . In the disengaged position, the restraining member  20  is permitted to move through its fill range of motion. 
     To allow the improved Star-style device shown in FIGS. 21-24 to only lock the restraining member in its vertical position for a pull away, yet provide for “floating” operation at other times, some means for determining when a pull away is occurring should be coupled to the locking device so that it is activated only when a pull away is occurring. Toward that end, the conventional Star-style unit includes a sensor member  38  that is pivotally mounted about the restraining member  20 . As seen most clearly in FIGS. 23 and 24, the sensor member  38  moves between a first position (FIG. 23) and a sensing position (FIG. 24) in response to the restraining member  20  moving upward into engagement with the ICC bar (the ICC bar pushes the sensor member  38  to the sensing position). The pawl  610  is operatively connected to the sensor member  38  such that it is in the disengaged position when the sensor member is in the sensing position (i.e. when an ICC bar B is properly restrained). For a pull away, however, and as described in detail above, the restraining member and the ICC bar move vertically relative to each other, with the restraining member moving down. The pawl is thus also operatively connected to the sensor member  38  such that the pawl  610  moves to the engaged position as the sensor member  38  moves away from the sensing position. Thus, as a pull away occurs, forcing the restraining member down, the ICC moves out of contact with the shank portion  21  of the restraining member  20 , and the sensing member  38  moves away from the sensing position, thus engaging the pawl  610  with a toothed projection  600 , and locking the restraining member  20  in place vertically above the driveway, thus preventing the ICC bar B from being able to force the restraining member  20  further down and escape therefrom. The toothed projections  600  are depicted as preventing downward movement of the restraining member  20 , but allowing upward movement when the pawl  610  is engaged in one of the toothed projections. It will be appreciated that other configurations for both the toothed projections  600  and the pawl  610  could be used, including a configuration that would prevent both downward and upward movement of the restraining member  20  for engagement between the toothed projections  600  and the pawl  610 . 
     In this embodiment, the operative connection between the pawl  610  and the sensor member is in the form of a pin  620  projecting from the pawl  610 , and perhaps seen most clearly in the top view of FIG.  22 . The pin  620  is disposed so as to be engaged by the sensor member  38  as it moves toward the sensing position, thus pushing the pawl  610  away from an engaged position. The pawl is preferably biased toward the engaged position, in this case by means of a spring  630  disposed between the pawl  610  and a fixed structure mounted adjacent the spring. In addition to the sensor member  38  itself, a second bias-overcoming member is preferably provided, in this case in the form of a solenoid  640  which may be energized to move the pawl  610  away from its engaged position by pulling on a shaft  650  attached thereto. Without the solenoid  640 , the restraining member  20  would not be able to move to a stored position after loading or unloading of the vehicle was completed since as soon as contact between the shank  21  and the ICC bar was lost (as is desired in this situation, since the vehicle desires to leave), the restraining member  20  would be locked in position vertically and prevent vehicle departure. Preferably, operation of the solenoid  640  or other bias-overcoming means is tied into the control box for the device such that the solenoid is actuated at least when the button to release the restraint is pushed. 
     It should be noted that this improvement to the Star-style device is not limited to that specific restraint. Rather, the invention is also broadly directed to a more general vehicle restraint that includes a restraining member and a sensor member operatively coupled to the restraining member for moving to a sensing position in response to movement of the restraining member to a restraining engagement of an ICC bar. A locking mechanism is also provided that is responsive to movement of the sensor member away from the sensing position to lock the restraining member against at least downward movement. Such a locking device is not limited to the mechanical locking device shown in relation to the Star-style restraint. For example, in a restraint device that is biased upwardly by a conventional wire-formed spring, a gas spring, a hydraulic cylinder, or other biasing means, a lock device could be provided to lock the spring or cylinder for movement of the sensor member away from the sensing position. The operative connection between the sensor member and the locking device could be electrical or mechanical. Other alternative means for locking a restraining member against downward movement in response to the sensor member moving away from the sensing position will occur to one of skill in the art. As in the improved Star-style restraint, such structure provides the restraining member with “floating” operation for normal conditions, yet also prevents further downward movement of the restraining member when relative vertical motion between the ICC bar and the restraining member allows the sensor member to move away from the sensing position. Again, however, not all restraints require such a locking mechanism to effectively and safely restrain a vehicle. Nor are all restraints practicably amenable to such modification. 
     An alternative improvement to the Star-style restraint, and which also allows for “floating” operation of the restraint until a pull away, is shown in FIGS. 25-27. This improvement takes advantage of the canting of the restraining member that we have observed and which was discussed in regard to FIGS. 7-9. As stated there, the canting of the restraining member  20  causes the faces  26  and  27  of the follower  25  to engage the faces  31 ,  32  of the track  30 . According to this embodiment of the invention, the frictional engagement between these surfaces in enhanced by providing a projection  670  on one or both of the surfaces  26 ,  27  that bites into one of the faces of the track  30 . FIG. 26 shows such a biting member  670  disposed in face  27  to bitingly engage the front surface  32  of the track  30  when the restraining member is canted. A detailed view of the biting member  670  is shown in FIG. 27, which shows that the member  670  is threadingly received in a bore or other receptacle formed in the surface and may illustratively include sharp surfaces  671 ,  672  to enhance the biting action. At the same time, the biting member  670  is disposed such that it does not engage the track  30  during normal operation of the restraint, as is shown in FIG.  25 . It is only when a pull away cants the restraining member  20  that the biting member engages the track to lock the restraining member  20  in its vertical position, thus preventing further downward movement and ensuring that the ICC bar B stays captured thereby. 
     There have thus been disclosed improvements to the Star-style restraint, as well as novel vehicle restraints or components using similar concepts. The resulting devices exhibit enhanced ability to restrain a vehicle&#39;s ICC bar during a pull away.