Abstract:
An Improved Bus Seat Safety Restraint is disclosed. The preferred safety restraint comprises a padded U-shaped bar that has indexed stops at stowed, in-use and lower locked positions. The bar locks and restrains the passenger when the vehicle experiences a side or front collision, or if the vehicle rolls over. The bar preferably has a single, fixed pivot point. The bar further comprises a padded thigh pad that is height-adjustable to provide greater comfort to a wide variety of body shapes and sizes. Still further, the restraint bar system is installable and easily aligned on both new and existing buses and other mass transportation vehicles.

Description:
This application is a continuation of application Ser. No. 09/005,660, filed Jan. 12, 1998, now pending. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to vehicle passenger safety restraints and, more specifically, to an Improved Bus Seat Safety Restraint. 
     2. Description of Related Art 
     Mass transportation vehicles such as buses have been widely used in virtually every city and town in the developed world for decades. Generally speaking, these vehicles typically include two or more columns of bench seats aligned one behind the other with a minimum necessary distance between a seat and the seat behind it. It is uncommon to find automobile-type lap or shoulder restraints for the passengers on public transportation vehicles, apparently because passengers repeatedly fail to engage the belts, either due to carelessness or due to perceived discomfort. In general, then, there is not currently a widely used restraint system to prevent passengers of mass transportation systems from being tossed from their seats in the event of a vehicle collision or rollover. 
     This problem is particular egregious in the case of school buses. Many children ride the bus to and from school five days a week in all weather, traffic and road conditions. The high frequency of ridership under a variety of conditions indicates that it is inevitable that more children passengers will experience a collision while riding a bus than virtually any other passenger group. This is exacerbated by the fact that children can tend to be particularly unruly while riding the bus to and from school; the children cannot be relied upon to engage the current safety restraints, even if they were provided. What is needed, therefore, is a safety restraint system for vehicles with bench seats that is easy to use and to be monitored. 
     Majerus, U.S. Pat. No. 4,681,344 sought to solve this problem. The Majerus unit comprises a hinged, U-shaped bar attachable to the legs of each forward seat in a column and a releasable belt which holds the bar in a lowered position, laying across the passengers&#39; laps, restraining them from striking the seat in front of them. When not in use, the Majerus belt is released, and the bar is pivoted up to the stowed position. There are three serious problems with the Majerus system: (1) the locking belt system is as difficult to enforce as a common lap belt—if the passenger pulls down the bar (i.e. to mislead the driver into believing that the bar is engaged), but fails to lock the belt, the system will not provide any restraint; (2) the Majerus belt extends from the bar to the seat at the aisle side of the seat, thereby trapping the restrained passengers in the seat until the belt is released; and (3) the system relies upon the passenger to adjust the belt until the bar is in the proper position—if the belt is left too loose, the bar won&#39;t provide restraint to the passengers, and may even be a hazard. What is needed, therefore, is a bus passenger safety restraint that is easily engaged, automatically adjusted, and easily verified as such by the bus driver. This system should further permit the passengers to easily egress in case of system malfunction. 
     Amabile, U.S. Pat. No. 4,796,913 sought to solve some of the Majerus problems. The Amabile device is also a hinged U-shaped bar attached to the next seat forward. The Amabile device differs from Majerus in that it attaches to the seatback frame directly and does not require a belt for engagement. The Amabile system comprises a pair of pivoting cam hinges at each end of the U-shaped bar attached to either side of the forward seatback frame. These cam hinges define three bar positions: an upper limit (stowed position), a lower limit, and a lower locked limit. The Amabile bar is automatically engaged in the lower locked limit position whenever the restrained passengers&#39; inertia forces the bar forward and into the lower locked cam in the hinges. 
     One serious problem with the Amabile system is that it is only responsive to a passenger accelerating forward relative to the seats, such as in a front-end collision. The Amabile bar will not restrain the passengers in the event of a side collision, or in a bus rollover. Furthermore, the Amabile bar is not height-adjustable by the passengers for their particular thigh height. Once installed, the Amabile cam hinge has a set locked position that cannot be adjusted; it is conceivable that a passenger with sufficiently large thighs will prevent the bar from dropping down low enough to engage if a collision occurs. Finally, the Amabile bar is difficult to install in existing buses. In order to activate both cam hinges (i.e. on both ends of the bar), the cams must be aligned with each other to a very close tolerance. Misalignments due to seat frame bending or simply inconsistent installations may create a situation where one hinge&#39;s cam locks while the other hinge doesn&#39;t. What is needed, therefore, is a safety restraint system that engages and locks in front, and side collisions, and even in the event of vehicle rollover. The system should be easily installed and aligned on existing buses, and further should provide adjustability for differing passenger body types. 
     SUMMARY OF THE INVENTION 
     In light of the aforementioned problems associated with the prior devices, it is an object of the present invention to provide an Improved Bus Seat Safety Restraint. The preferred safety restraint will comprise a padded U-shaped bar. The bar has indexed stops at stowed, in-use and lower locked positions. It is an object that the bar lock and restrain the passenger when the vehicle experiences a side or front collision, or if the vehicle rolls over. It is a further object that the bar have a single, fixed pivot point. The preferred bar will further comprise a padded thigh pad that is height-adjustable to provide greater comfort to a wide variety of body shapes and sizes. It is a still further object that the restraint bar system be installable on both new and existing buses and the like. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which: 
     FIG. 1 is a side view of a pair of school bus seats, the forward of which has a preferred device of the present invention installed thereon; 
     FIG. 2 is a back view of the forward seat of FIG. 1 depicting the restraint bar in the in-use and lower locked positions; 
     FIG. 3 is a back view, similar to FIG. 2, depicting the restraint bar in the stowed position; 
     FIG. 4 is a partial cutaway side view of a preferred aisle-side hinge assembly as it is attached to the front seat of FIG. 1; 
     FIGS. 5A and 5B are partial side views of the aisle-side hinge assembly of FIG. 4, depicting the rest and engaging positions of the weight; 
     FIG. 6 is a partial cutaway top view of the hinge assembly of FIGS. 4 and 5; 
     FIG. 7 is a partial cutaway bottom view of the hinge assembly of FIGS. 4-6; 
     FIG. 8 is a partial back view of the preferred hinge assembly of FIGS. 4-7; 
     FIGS. 9A and 9B are partial perspective views of the preferred shaft and spring of FIGS. 4-8 depicting the relationship between the spring and the indexing notches on the shaft; 
     FIGS. 10A and 10B are perspective views of the preferred restraint bar of the present invention depicting the action of the preferred thigh pad; and 
     FIGS. 11A and 11B are cutaway side view of the thigh pad of FIGS. 10A and 10B and the restraint bar of previous figures. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide an Improved Bus Seat Safety Restraint. 
     The present invention can best be understood by initial consideration of FIG.  1 . FIG. 1 is a side view of a pair of school bus seats  10  and  12 , with the forward seat having a preferred device of the present invention installed thereon to restrain the person(s) seated in the next-rear seat  12 . The device includes a U-shaped restraint bar  14  in hinged attachment to the seat back  16  of the forward seat  10 . The restraint bar  14  may be pivoted into a stowed position  18  to permit passenger ingress to and egress from the next-rear seat  12 ; the hinge assembly (see FIGS. 4-10) preferably provides an indexed stop to hold the bar  14  in the stowed position  18  until it is pulled down, presumably by a passenger seated in the next-rear seat  12 . When pulled down from the stowed position  18 , the bar  14  will drop until it either reaches the passengers&#39; thighs or reaches an indexed in-use position  20 . The system further preferably defines a lower locked position  22  that will permit the bar  14  to approach the seating surface  24  of the next-rear seat  12  no closer than the minimum thigh distance  26 . This minimum thigh distance  26  may be defined by law to be a distance sufficient to prevent crushing the passengers&#39; legs. The system may include a bulkhead stop  27 , which is essentially a padded protrusion mounted to the bulkhead of the vehicle, positioned to prevent the bar  14  from traveling down further than the lower locked position  22 . If the seat back  16  happens to be deformed, such as in the event of a heavy rear impact, the bulkhead stop  27  will prevent the bar  14  from violating the minimum thigh distance  26 . It should be appreciated that one critical aspect of the present invention is the novel pivoting-and-locking action of the bar  14  that defines a single fixed hinge axis  28  about which the bar  14  pivots. 
     Turning to FIG. 2, we can view the restraint bar  14  from another perspective. FIG. 2 is a back view of the forward seat  10  of FIG. 1 depicting the restraint bar  14  in the in-use and lower locked positions  20  and  22 , respectively. As can be seen, the bar  14  is U-shaped, with a center section  30  and aisle- and window-side ends  32  and  34  extending forwardly where they are pivotally attached to the seatback  16 . As discussed above, the restraint bar  14  may pivot along the hinge axis  28  to in-use and lower locked positions  20  and  22 , respectively. 
     FIG. 3 is a back view, similar to FIG. 2, depicting the restraint bar  14  in the stowed position  18 . In the stowed position  18 , the bar&#39;s center section  30  extends above the top of the seat back  16  such that it is easily viewable by the bus driver desiring to check whether the bar  14  is being employed properly by the passenger. 
     Now turning to FIG. 4, we might discuss the novel functioning of the present invention. FIG. 4 is a partial cutaway side view of a preferred aisle-side hinge assembly  36  as it is attached to the front seat of FIG.  1 . It should be appreciated that both the aisle-side and window-side hinge assemblies are identical mirror images of one another; we simply focus on the aisle-side assembly  36  here for ease of understanding. 
     The hinge assembly  36  comprises a plurality of mounting brackets  38  made from a hardened material, such as steel, attached to the typically tubular frame  40  of the seat back  16 . The hinge assembly  36  can be attached at virtually any height along the seat frame  40  that is desired, depending upon the particular installation. A critical feature of the hinge assembly  36  is that virtually all components, with the possible exception of the end of shaft  42 , are contained within the seat cover  44  and/or the padding  46  surrounding the frame  40 . As such, all mechanical components of the hinge assembly  36  are hidden from view and protected from tampering and against injuring the passengers. Another preferred hinge assembly  36  may comprise “U”-bolts or other substitutes for the mounting brackets  38 , depending upon the particular installation requirements. 
     The restraint bar end  32  comprises, a frame  48  surrounded by rubberized padding thereover, and is fixedly attached to the shaft  42 , such that when the shaft  42  rotates on the hinge axis  28 , the restraint bar (see FIGS. 1-3) pivots upwardly and downwardly. The shaft  42  is further configured with a plurality of teeth  52  formed on its surface. A jaw member  54  is pivotally attached to the mounting brackets  38  in the vicinity of the shaft  42 . The jaw member  54  is also formed with teeth  56  thereon opposite the shaft teeth  52 . It should be obvious that if the jaw member  54  is pivoted such that the jaw teeth  56  engage the shaft teeth  52 , the shaft  42  will be prevented from rotating, which in turn will prevent the restraint bar (see FIGS. 1-3) from moving. As designed, the system may be configured to engage in the event of heavy braking or swerving of the vehicle, prior to any actual impact; it is unnecessary that the passenger strike the bar (see FIGS. 1 and 2) in order to engage the locking system. 
     The jaw teeth  56  are caused to engage the shaft teeth  52  when the jaw member  54  is forced to pivot by the rocking pad  58 . The rocking pad  58  is attached to, and rides on, the fulcrum  60 , such that when the fulcrum  60  is caused to rock back and forth, the rocking pad  58  will urge the jaw member  54  towards the shaft  42 . The fulcrum  60  rides atop the fulcrum bracket  62 , which is essentially a metal bracket attached to the mounting brackets  38  to provide a substantially horizontal surface upon which the fulcrum  60  may rest. Extending downwardly from the fulcrum  60  is the pendulum rod  64 , at the end of which is a weight  66 . It should be apparent, then, that the system functions like a pendulum such that when impact or gravitational forces cause the weight  66  and pendulum rod  64  to leave vertical alignment by a sufficient amount, the fulcrum  60  will rock, thereby causing the rocking pad  58  to urge the jaw member  54  towards the shaft  42  until the jaw teeth  56  engage the shaft teeth  52 . 
     To prevent the system from being damaged by excessive downward force being place on the restraint bar (see FIGS.  1  and  2 ), such as if a large child sits of bounces on it, the preferred hinge assembly may also include a pin  63  protruding radially from the shaft  42  and configured to engage a shaft stop  65  to prevent further rotation of the shaft  42 . Further detail regarding the shaft stop pin  63  and the shaft stop  65  is provided below in connection with FIGS. 5,  6  and  8 . 
     In order to prevent the bar  14  from being locked in position when the vehicle is struck from the rear, a weight stop  67  is provided. The weight stop  67  may be a protrusion from the mounting bracket  38 , or may actually be a feature of a metal enclosure for the hinge assembly  36  (not shown). The weight stop  67  is positioned to prevent the weight  66  from traveling backwards beyond the rest position (see below). 
     FIGS. 5A and 5B are partial side views of the aisle-side hinge assembly of FIG. 4, depicting the rest and engaging positions  68  and  70  of the weight  66 , provided to further illuminate the novel functioning of the present invention. As can be seen in FIG. 5A, the pendulum rod  64  is in vertical alignment with the fulcrum  60  and the weight  66 ; the weight  66  being in the rest position  68 . In this rest position  68 , the jaw member  54  is also “at rest”, its teeth  56  are not engaged with the shaft teeth  52 , and the shaft  42  is free to rotate about the hinge axis  28 . 
     FIG. 5B depicts the weight  66  in the engaging position  70 , wherein the weight  66  is no longer in vertical alignment with the pendulum rod  64  and the fulcrum  60 . In this case, the weight  66  has traveled forward, such as from the vehicle suffering a front-end collision. When the weight  66  reaches the engaging position  70 , the attached components have forced the jaw member  54  to pivot around the pivot shaft  72  until the jaw teeth  56  have engaged the shaft teeth  52 . Furthermore, if the vehicle drives up or down a severe enough incline, the weight  66  might also reach the engaging position  70 , thereby locking the shaft  42  (and restraint bar) from movement. This is an added safety benefit not available with the prior devices. 
     Still further, it should be understood that the actual location limit setting of the engaging position  70  is configurable by altering the length of the pendulum rod  64 , for example. It should also be appreciated that once the jaw teeth  56  and shaft teeth  52  are engaged, the shaft  42  will be released for rotation after the weight  66  drops to the rest position  68  and any rotational force on the shaft  42  is relieved (such as by slightly lifting the restraint bar). It can further be seen that the weight stop  67  will prevent the weight  66  from traveling backwards sufficiently past the rest position  68  to cause the jaw  54  to engage the shaft  42 . 
     FIG. 6 is a partial cutaway top view of the hinge assembly  36  of FIGS. 4 and 5. As depicted here, the mounting brackets  38  are preferably attached to the frame  40  by a plurality of mounting bolts  74 . The shaft  42  is also configured to rotate in one of the mounting brackets  38  around the hinge axis  28 . Another aspect shown here is the novel means for attaching the restraint bar  14  to the shaft  42 . The preferred restraint bar  14  is formed with an adapter  78  at its end. The adapter  78  is of the same cross-section as the shaft  42 , and has a mating surface configured to be accepted by a V-notch  76  formed in the end of the shaft  42 . As long as the adapter  78  is firmly attached to the shaft  42 , such as by a bolt or the like, the mating surface of the adapter  78  will engage the V-notch  76  to prevent rotational motion between the shaft  42  and the bar  14 . To remove the restraint bar  14 , one need merely remove the attaching means (i.e. a bolt), and the adapter  78  will slip out of the V-notch. 
     Also depicted in FIG. 6 is the spring  80 . The spring  80  attaches between the shaft  42  and the mounting bracket(s)  38  to urge the shaft  42  to rotate and cause the restraint bar  14  to be biased towards the stowed position (see FIGS.  1 - 3 ). This spring action will assist the passenger in lifting the bar  14  up and out of the way, but will not be strong enough to cause the bar  14  to lift without manual passenger assistance. Furthermore, the shaft stop pin  63  is depicted located on the restraint bar  14  side of the hinge assembly  36  to reduce the torque generated within the system when engaging the shaft stop (see FIGS.  4  and  8 ). 
     FIG. 7 is a partial cutaway bottom view of the hinge assembly  36  of FIGS. 4-6 presented to show additional detail regarding these components. It can be seen that the preferred jaw member  54  extends over substantially the entire exposed length of the shaft  42 , such that all resultant forces created between the jaw member  54  and the shaft  42  when their teeth (see FIGS. 4-5) are engaged are adequately transferred to the seat frame  40 . Further depicted is the beveled aperture  82  formed in the fulcrum bracket  62  to allow the pendulum rod (see FIGS. 4-5) to pass through and attach to the fulcrum (see FIGS. 4-5) and still permit the weight  66  a full range of motion. 
     FIG. 8 is a partial back view of the preferred hinge assembly  36  of FIGS. 4-7, provided to give insight into the response of the hinge assembly  36  in the event of a side collision to the vehicle. As discussed above, when at rest, the weight  66  will hang in vertical alignment with the pendulum rod  64 , such that the rocking pad  58  does not push the jaw member  54  to engage its teeth with those of the shaft  42 . When a lateral- or side-impact to the vehicle causes the weight  66  to move sufficiently left or right to reach one of the lateral engaging positions  84 , the fulcrum (see FIGS. 4-5) will cause the rocking pad  58  to push the jaw member  54  upwardly until its teeth are engaged with the shaft teeth (see FIGS.  4 - 5 ). Here, the shaft stop pin  63  and shaft stop  65  are also depicted; as can be seen, the preferred shaft stop  65  is inserted in a pair of cooperating apertures (not shown) in the mounting bracket  38  to provide a rigid stop for the shaft stop pin  63  and shaft  42 . 
     It should also be understood that vehicle rollover will also cause the weight  66  to reach one of the lateral engaging positions  84 , thereby engaging the jaw member  54  with the shaft teeth (see FIGS.  4  and  5 ). 
     Now turning to FIGS. 9A and 9B, which are partial perspective views of the preferred shaft  42  and spring  80  of FIGS. 4-8, we might discuss the relationship between the spring  80  shaft  42 . In its preferred form, the spring  80  will be formed with an arch  86  near its center. The arch  86  defines an indexing segment  88  at its apex. The indexing segment  88  is located and configured to engage the in-use indexing notch  90  and the stowed indexing notch  92 , which are formed in the shaft  42 . In addition to urging the restraint bar towards the stowed position, the spring  80  interacts with these indexing notches  90  and  92  to provide positive “stops” at the in-use and stowed positions. Other intermediate stops may be provided by forming the appropriate notches in the shaft  42 . Once “stopped”, the user need merely exert a minimum amount of force on the restraint bar in order to pop the indexing segment  88  out of the in-use indexing notch  90 . FIG. 9B depicts that the shaft  42  has now rotated until the indexing segment  88  has engaged the stowed indexing notch  92 . The shaft teeth  52  are also depicted to show that they do extend over a substantial portion of the shaft&#39;s  42  length. The indexed rotation of the shaft  42  will provide smoother, less jarring engagement than the prior devices. 
     Finally, turning to FIGS. 10A and 10B we may discuss still another novel aspect of the present invention. These figures are perspective views of the preferred restraint bar  14  of the present invention depicting the action of the preferred thigh pad  94 . The thigh pad  94  may simply be an oblong pad formed over the center section  30  of the restraint bar  14 . The thigh pad  94  is rotatable in the upward direction  96  and the downward direction  98  in order to provide the user with a comfortable place upon which to rest his or her arms and/or hands. Furthermore, the thigh pad  94  may be rotated to provide greater or less distance between the restraint bar  14  and the passengers&#39; thighs, if desired. 
     While only the pendulum-type locking mechanism has been described heretofore, it is understood that (1) other locking mechanisms are conceived of for use in this invention, such as other forms or arrangements of jaw members and shafts; and (2) any accelerometer-type sensing system beyond the pendulum-fulcrum system may be used, depending upon the details of a particular installation. 
     Now turning to FIGS. 11A and 11B, we may discuss the details of the novel thigh pad  94  of the present invention. FIG. 11A is a cutaway side view of the thigh pad of FIGS. 10A and 10B, and FIG. 11B is a partial cutaway side view of the restraint bar  14  of the previous figures. The thigh pad  94  comprises a thigh pad frame  100 , preferably made from metal or other durable material. The frame  100 , like the rest of the restraint bar  14 , is surrounded by padding  50 , such as is commonly used in prior restraint bars. The pad  94  further has a durable cover  102  over the padding  50  and frame  100 , made from material which resists cutting, tearing or wear. 
     The frame  100  is further defined by a bore  104 , configured to accept the restraint bar frame  48 , and further includes a keyway  106 . The keyway  106  is cooperates with the key  108  such that the thigh pad  94  is permitted to rotate through it desired range of rotation  96  (in this case 130 degrees). The assist in assembly of the thigh pad  94 , the frame  100 , padding  50  (and possibly other elements) may be divided into two or more sections that are assembled around the restraint bar frame  48 . 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.