Abstract:
An extended school stop sign, which may but need not be retrofitable, and barrier is mounted on a conventional school bus stop sign and extends further into the adjacent lane to reduce instances in which motorists pass a stopped school bus. A first frame is permanently secured to conventional stop sign mechanism. A second breakaway frame or arm is attachable to and detachable from the first frame, and extends beyond the conventional stop sign. If a vehicle strikes the second frame, it separates without significantly damaging the conventional stop sign mechanism. The extension arm can be moved between a retracted and extended position by the same mechanism that opens and closes the conventional stop sign, or with a new mechanism entirely.

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
     This application claims the benefit of prior U.S. Provisional Patent Application 62/005,954 filed May 30, 2014. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of the Invention 
     This invention relates generally to an apparatus which extends a STOP sign on the driver&#39;s side of a school bus. It is designed to work in conjunction with the existing STOP sign, swinging to an outstretched position to nearly the center to the adjoining lane where the bus is stopped. The Stop Safety Breakaway Arm Extension is an auxiliary device designed to assist other vehicle drivers in becoming aware that the school bus has stopped to load or discharge passengers. The invention works in conjunction with the existing bus STOP sign mechanism, or could work independently thereof. 
     2. Description of the Prior Art 
     School buses serve to pick up or discharge children attending a school at various points along a route running through the community in which the school is located. As a safety measure, school buses have for many years been equipped with a stop sign mechanism, either manually or automatically controlled. This mechanism is engaged through a hinged connection that allows the sign to be folded against the body of the bus when the bus is not stopped for passenger entry or egress through a door. The basic requirements are defined in a Society of Automotive Engineers (SAE) J1133. The bus stop sign mechanism acts to swing out the stop sign from its normally retracted position against the side of the bus to an outstretched position, providing a signal alerting drivers of nearby vehicles that children are entering or leaving a bus. 
     The current octagonal bus STOP sign has a hinge plate mounted on the bus to which the STOP sign is usually mounted with 4 bolts or studs. This hinge plate allows the STOP sign to swing out perpendicular to the side of the bus. U.S. Pat. Nos. 2,384,689 and 3,094,683 are illustrative of manually-operated school bus sign devices, while U.S. Pat. No. 2,252,529 discloses a hydraulically operated school bus sign. There are also motor operated, vacuum operated, air pressure operated school bus signs either deployed manually or automatically when the door is opened. One Prior art hinge is shown in  FIG. 17 . 
     One practical drawback of any of these units is that many drivers ignore or do not see them. What is needed is a device or mechanism to work in conjunction with the existing STOP sign to heighten the awareness of other drivers of the bus driver&#39;s intention to stop and load or discharge passengers. Currently, the vehicle which they want to stop can continue with no significant warning or repercussions. Thus, a child can either cross into the path of a moving vehicle while entering or exiting from a school bus. The current school bus configuration with STOP sign extended offers little or no protection to the child and no physical deterrent or barrier to the driver approaching the stopped school bus. 
     A structural drawback to the original art design school bus STOP sign mechanism is that it is not strong enough, nor does it have sufficient quality bearing hinge points to allow for a heavier, stronger arm to extend out without redesigning and providing additional support at both the top and bottom of the arm. 
     The major drawback to the current stop sign is that it signals to a child that it is now safe to cross a street, when indeed it is not, and a vehicle can readily pass the stopped school bus and hit the child either injuring or killing the individual. 
     SUMMARY OF INVENTION 
     The Stop Safety Breakaway Arm Extension according to this addresses these deficiencies. Specifically this device provides a mechanical method for control of traffic which the nearby vehicles will find as a deterrent or barrier to passing a stopped school bus. This should in and of itself reduce significantly the passing of stopped school buses and thus reduce the number of injured and killed children associated with this violation of motor vehicle laws. In response to the previous mentioned situations, the main objective is to prevent injury or death to an individual by providing a relatively low cost traffic control method. This will have the same response time as the original mounted mechanism on the bus, as it is immediately attached to the same bracket as the current sign. The Stop Safety Breakaway Arm Extension is light in weight, easily and quickly installed and will wire into the existing bus stop sign light harness. 
     One of the main features of the preferred embodiment of this invention is that one can retrofit the existing bus STOP arm mechanism without making any significant changes to the existing mechanism, (only replacing the supporting sign bolts and or nuts). The bus STOP sign is attached with a hinge plate to allow it to swing or rotate out perpendicular to the bus. The original holes or studs for holding the STOP sign are used to hold the new invention in place. Therefore this can be used by all existing school buses, not just new ones as they are replaced. The current mechanisms for moving the current STOP sign are significantly adequate to control this attached invention. Thus no new mechanism is necessary to make this operable. The complete breakaway frame AAA weighs just under 6 pounds as herein configured. The existing system will operate the whole extended arm whether it is manually operated, or operated by hydraulic, air, vacuum, motor or other means. In order to keep the cost down, no redesign of the original mechanism is provided. The arm was designed with light weight material and two additional bearing/support points were added. 
     According to one aspect of this invention, a deployable sign assembly for use on a school bus is extendable and retractable from a traffic lane adjacent the school bus when stopped, to protect children entering or leaving the school bus. the sign assembly comprises a barrier mountable to swing relative to the school bus between a barrier retracted position and a barrier extended position during deployment of the sign assembly. The barrier will extend into the traffic lane adjacent the school bus when in the barrier extended position by a distance sufficient to obstruct motorists trying to pass the stopped school bus in the adjacent lane when the school bus is stopped. This extended barrier will protect children crossing the traffic lane adjacent the school bus when stopped. The barrier is mountable on the school bus at a height at least equal to the eye line of a motorist in a passenger automobile so as to be readily visible to any approaching motorist. The barrier also includes an illuminated stop sign. The barrier is also releasable if struck by a vehicle passing the stopped school bus in the adjacent lane. 
     According to another aspect of this invention, a safety arm for use on a school bus will prevent motorists from passing the school bus when stopped and to protect children crossing a road to board or exit the school bus. The safety arm comprises a first frame mountable adjacent a side of the school bus. The first frame is pivotable between a retracted position and an extended position. A second frame can be attached to the first frame so that the second frame extends laterally beyond the first frame with a distal stop sign mounted on a remote end of the second frame. The first frame and the second frame move in unison between the retracted and extended positions. The second frame is releasable from the first frame by an impact only striking the second frame. If the second frame is struck by a vehicle, the first frame remains mounted on the side of the school bus and the second frame is released from the first frame. 
     A safety breakaway arm extension in accordance with this invention is intended for use with an operable stop sign on a vehicle. The arm extension comprises a first arm member securable for movement with the operable stop sign as the operable stop sign moves between an operable stop sign retracted position and an operable stop sign extended position. A second arm member can be attached to the first arm member, but not to the operable stop sign. The first and second arm members are movable between an arm extension retracted position and an arm extension extended position with movement of the operable stop sign between the operable stop sign retracted position and the operable stop sign extended position. The second arm member extends beyond the operable stop sign in the arm extension extended position and the second arm member can be positioned along one side of the vehicle in the arm extension retracted position. The second arm member has a length sufficient to extend into a traffic lane adjacent the vehicle. The second arm can be released from the first frame by an impact on the second frame, not striking the first frame or the operable stop sign. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to provide a better understanding of the invention, as well as other objects referred to and further features thereof, reference is made to the following detailed description to be read with the accompanying drawings enclosed. 
         FIG. 1  shows a conception of the arm extended when children would be crossing and a vehicle being blocked by the safety arm invention. 
         FIG. 2  is the overall view with the school bus on the left. This school bus configuration with STOP sign extended with the invented Stop Safety Breakaway Arm Extension in place, providing deterrent to the driver approaching the stopped school bus. This shows embodiment A, embodiment B and C are similar. 
         FIG. 3  is Frame A that supports Frame AAA 
         FIG. 4  is Frame B that supports Breakaway Arm option BBB 
         FIG. 5  is Frame C that supports Breakaway Arm option CCC. 
         FIG. 6A  shows a Lower bracket and ball stud bearing.  FIG. 6B  shows a retraction device and supporting stud. 
         FIG. 7  is Breakaway option AAA Safety Arm without the second STOP sign attached. 
         FIG. 8  is Breakaway option BBB Safety Arm without the second STOP sign attached. 
         FIG. 9  is Breakaway option CCC Safety Arm without the second STOP sign attached. 
         FIG. 10  is a rear view with the arm extended Option A. (embodiment B and C are similar). 
         FIG. 11  is a front view with the arm extended Option B. (embodiment A and C are similar). 
         FIG. 12  is a front view of Option C. This shows Frame C with modified support holes, and Frame CCC. This also shows half of the hinge of a more robust system holding the frames without any sign close to the bus. 
         FIG. 13  shows the complete Stop Safety Breakaway Arm Extension in an exploded viewpoint option A. (options B and C are similar). 
         FIG. 14A  shows an adhered cushioned stop to prevent lights and sign from hitting bus when closed.  FIG. 14B  shows a vibration support and  FIG. 14C  shows a mounting bracket. 
         FIG. 15  a schematic of the electrical features of this safety arm. 
         FIGS. 16A  and its continuation  16 B show a representative parts list for embodiment A, B or C. 
         FIG. 17  is a photograph of the original STOP sign mechanism. 
         FIG. 18  is a photograph of the complete new invention embodiment A, also showing original sign. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Each embodiment, or option of this extension arm barrier  100 ,  200 ,  300  has two main pieces. There is an attachment or mounting section A or B which bolts permanently to the existing STOP sign mechanism  50  comprising a conventional operable sign  51  mounted on a hinge  52  so that the operable sign can be pivoted between a retracted position and an extended position. The third embodiment including a mounting frame C would be mounted on a new hinge  41  and would not be retrofitable to the existing stop sign mechanism. Each extension arm barrier or safety arm  100 ,  200  and  300  is preferably mounted at the same height as the conventional, pivotal stop sign currently employed on school buses. In each of the three representative embodiments discussed herein, existing holes in the STOP sign mechanism  52 , preferably in the existing hinge mechanism, allow attachment of a mounting frame A or B. A breakaway section or extension arm or frame AAA, BBB or CCC respectively is attachable within an outer section of the first mounting frame A, B or C respectively. Stabilizing points  27  as shown in  FIG. 7  to act as a hinge point, and shear attachment members  28  as shown in  FIG. 17  to secure the breakaway extension arm AAA, BBB or CCC to the respective mounting frame A, B or C. This extension arm or frame AAA, BBB, CCC has an additional sign  31  with lights  30  mounted on a distal end thereof. The stabilized or mounting frame A, B, C is attached to the bus permanently, and breakaway extension arm or frame AAA, BBB, CCC will upon impact will breakaway from the respective mounting frame A, B, C. In case of an accident or deliberate abuse, the shear members  28  will snap off, allowing the extension arm or frame AAA, BBB, CCC to pivot on the pivot points and breakaway from the mounting frame A, B, C disconnecting the electrical circuit connecting the lights  30  to a source of electrical power on the bus and fall to the ground. These together extend breakaway arm or frame AAA, BBB, CCC out nearly into the middle of the next lane, approximately 6 to 7 feet from the side of the bus; at about the same height as the original, operable and pivotal STOP sign  51 . Each of the embodiments of the invention has the common element of an extension arm or frame AAA, BBB or CCC on the side of the bus that contains an outer STOP sign  31  and moves in concert with the operable STOP sign  51  and stop sign mechanism  50 . This provides a traffic control device for use on school buses which locates the additional traffic control stop sign  31  in the normal field of vision of approaching traffic, yet is robust, and can be extended and retracted automatically and rapidly, and substantially does not suffer wind, acceleration or deceleration damage during movement of the school bus. In the preferred embodiment of this device an additional STOP sign  31  with flashing lights  30  will be in the line of sight of an approaching driver and will extend to the middle of the lane which the vehicle would pass the bus from while either approaching or overtaking from the rear of the bus. The extendable arm AAA, BBB or CCC will also form a barrier between the approaching motorist and motor vehicle and children crossing a street to board or leave the school bus. 
     Each embodiment of the safety barrier  100 ,  200 ,  300  will attach to the existing stop sign apparatus hinge bracket  52 , or alternatively to a new hinge  41 , and swing into the path of the vehicle with a flashing stop sign  31  nearly midpoint to the lane in which the traffic is coming. This will provide a physical deterrent to a vehicle passing the stopped school bus. There will then be two flashing stop signs  31  and  51  and a physical barrier, which must be ignored or avoided when a driver attempts to pass the stopped school bus. 
     Although a vehicle could still pass the school bus and hit a child or individual, it could incur an accident with the extended arm AAA, BBB or CCC of the school bus as a result. From an engineering point of view, any device designed to improve safety, should never become a hazard in and of itself. In order to limit damage to the mechanism operating the extension arm AAA, BBB, CCC or to the vehicle hitting the Stop Safety Breakaway Arm Extension sign and barrier  100 ,  200 ,  300 , a breakaway point has been designed, which will enable the bus to continue even after a vehicular accident with the extended barrier  100 ,  200  or  300 . The original sign  51  should still operate and flash normally. The Stop Safety Breakaway Extension Arm or barrier AAA, BBB or CCC will breakaway in the event that it is struck by a passing vehicle This breakoff point includes an electrical disconnect  38 . This extension arm AAA, BBB, CCC will also break away from the respective mounting frame A, B or C if forcibly moved relative to the operable stop sign mechanism  50 . 
     Budgetary issues, especially local school funding will always be an issue. As a result this invention provides a bus stop sign extension apparatus of simple, efficient and reliable design whereby it may be installed at a relatively low cost to the school system. To mount the first embodiment of this device  100 , for example, one would remove four bolts or nuts holding the existing STOP sign  51 , and replace these bolts with four longer bolts or appropriate nuts to hold the mounting frame A and the original, operable STOP sign  51 . Then the extension arm AAA is placed within the supporting mounting frame A and secured with the shear pins or frangible attachment members  28 . With the entire device attached the wiring harness  40 , carried by the extension arm AAA is connected to the bus electrical system powering the lights on the original operable stop sign  51 . 
     Three additional items are needed for installation. A lower bearing support bracket  33  is mounted in line with the existing bearing point of the original hinge  52 . A retraction cable is attached at approximately eight inches towards the rear of the bus from the hinge point but in line with the top of the retraction device. A vibration bracket  25  will be attached at the appropriate height along the side of the bus at approximately four inches from the new retracted stop sign  31 . Should an accident occur, and a breakaway happen, only the extension arm AAA, BBB or CCC of the device will need to be replaced. The original mounting frame A, B or C attached to the Bus STOP sign mechanism  50  will remain. This should save substantial time and funds in maintenance of the device. 
     Succinctly stated the extended arm AAA, BBB, CCC will swing out to an outstretched position when the original STOP sign mechanism  50  is activated and begins flashing its&#39; lights providing a second STOP sign  31  and additional flashing lights  30 . When retracted by the mechanism the entire barrier  100 ,  200 ,  300  will close against the side of the bus. The safety shear members  28  as shown in  FIG. 13  provide a weakening part of the structure, snapping off with impact, while having great tensile strength. The stabilizing points  27  shown in  FIG. 13  provide a solid, yet flexible hinge point without additional attachment. 
     This additional STOP sign  31  with flashing lights  30  provides a significant deterrent to other vehicles not to pass the bus during passenger entry or egress. 
     Three representative embodiments of this invention, and their component parts will now be described in more detail. It should be understood that this precise description of the assembly, the subassembly and the individual components is merely intended to comprise a description of each functional, but representative embodiment. Therefore the detailed information is representative only and the invention is not confined or restricted by this precise description. One of ordinary skill in the art would understand that there are numerous modifications that could be made without departing from the scope and spirit of the broader invention illustrated by this detailed representative description. Furthermore it should be understood that other modifications could be made. As an illustrative example, the metal frame construction might be replaced by the use of a one-piece extruded plastic frame, carbon fiber, or some or all of the frame components could be replaced with individual plastic or other material components. Another illustration of an alternative component could be the substitution of a spring loaded plunger, received in a detent for the shear pins  28  described herein. Even though the following details are in most, if not all respects non-limiting with respect to this invention, nevertheless this detailed description is believed to instructive. 
     The following is a description of each item or part used in this invention. In every case the use of types of material, size, weight, manner of connection, fasteners used, only reflect one representative alternative, and are not intended to be the only possibility. 
     A first attachment or mounting frame A can be fabricated of square steel tubing. Upper and lower horizontal tubing  7  and  8  are of equal in length and are made of ½″ square steel tubing. Each tubing section  7  and  8  is of sufficient length to ensure accommodation of the original STOP sign  51  plus have approximately four inches remaining beyond the surrounding square for support of the breakaway frame AAA. Both tubing members  7  and  8  have a hole drilled into it for the shear member  28 , which in this application currently is a nylon bolt. The distance along these frame sections  7  and  8  at which a hole is drilled is sufficient to provide a lever or moment arm which will result in development of a force of not less than forty pounds so that each shear member will be broken by only by a force of at least that magnitude. It is understood that the maximum wind resistance that would be encountered during normal and anticipated operation of a school bus or similar vehicle will result in application of a force of approximately fifteen pounds on each shear member  28 ._In this embodiment, the center of this hole is three inches from the outside of the corner of the frame. The tubing sections  7  and  8  have tapered ends primarily for cosmetic purposes. In addition tubing section  7  has a quarter inch hole drilled eighteen inches from the square end to accept a stud  32  on the retraction device  35  stud as shown in  FIG. 6 . 
     Vertical frame members  1 ,  2  and  9  are preferably identical are made of half inch square steel tubing and have a length sufficient to provide visual clearance to the enclosed original STOP sign. Frame members  1  and  2  have holes of an adequate size and placement to meet the bus bracket specifications, and the location of these holes can be modified for use on buses or vehicles having different structures. There are two additional 9/64″ holes drilled on the outside of frame member  9  to accommodate stabilizing pins  27 . These holes are oversize relative to the pins allowing for an easier release in case of accident, thus encouraging the breakaway action. The holes are drilled in exacting placement to match up with the stabilizing pins  27  in frame AAA, referred to in  FIG. 7 . 
     Center tubing section  3  is preferably made of half inch square steel tubing and of a length to accommodate the correct spacing of the holes in vertical sections  1  and  2  and is located at the midpoint to section  1 . 
     Support tubing member  4  is made of ¾″ square steel tubing at least four inches long, and is tapered at one end, primarily for cosmetic purposes. Support member  4  supports bearing angle iron  5  which is fabricated from ¾″ steel angle iron and can be two inches long. Support  5  in turn supports ball stud bearing  6 . 
     Ball stud bearing  6  is made of ½″ thick Lexan 1½″ by 2″, or other suitable bearing material with a ⅜″ spherical indentation, as shown in  FIG. 6 , to accept the ⅜″ ball stud part  34  as shown in  FIG. 6 . 
     Mounting frame A, as shown in  FIG. 3  is fabricated by welding the frame sections together. Vertical Frame Sections  1 ,  2  and  9  are parallel when the mounting frame A is welded, and horizontal sections  7  and  8  are also mutually parallel. In this embodiment, all angles are ninety degree right angles in order to correctly support the breakaway frame or arm AAA. The main function of the mounting frame A is to provide a permanent initial frame onto which the breakaway frame can be attached. This provides a means of separation of the extended sign from the bus if an accident should occur. 
     Frame or arm AAA, as shown in  FIG. 7 ) is the breakaway frame. One configuration of this is made of aluminum tubing to reduce weight. The breakaway arm AAA may however be made of other suitable material. As configured breakaway arm AAA weighs under 6 pounds. 
     Vertical frame member  16  is made of ¼″×¾″ flat aluminum. The length is determined by the vertical inside dimension of frame A. This dimension should be about 1/16″ less than the inside dimension of frame A. This is controls the shear affect. Vertical frame member  16  is drilled to receive quarter inch stabilizing pins  27 . These holes may be tapered to easier accommodate release if an accident would occur; thus releasing the breakaway frame AAA. These holes are within three inches of the outside corners of vertical frame member  16 . 
     Main vertical frame section  17  is ¾″ square aluminum tubing, which has a length determined by the vertical inside dimension of frame A. This should be about 1/16″ less than the inside dimension of frame A. Again this determines the shear effect. 
     Horizontal frame segments  14  and  15  are ¾″ square aluminum tubing that are four inches long. Horizontal segments  14  and  15  have quarter inch holes drilled three inches from the outside edge of the frame AAA to accommodate the shear bolts or pins  28 . 
     Inclined tubing members  19  and  20  are fabricated from equal sized ¾″ round aluminum tubing about thirty four inches long. 
     Frame components  18  and  21  are made of solid ⅜″ aluminum rod. These are structural members provide additional rigidity, and member  18  is located near the middle distance between frame components  17  and  22 . 
     Outer vertical member  22  is made of ¾″ square aluminum tubing and can be eight and one-half inches long. Two quarter inch holes are drilled spaced six inches on center, equal distance from the ends. These holes are for mounting the new STOP sign  31 . 
     The components of this frame AAA are welded together and all openings sealed except for that of outer vertical member  22  which will have wiring installed. Frame components  15  and  20  are welded together such that this subassembly functions as a continuous conduit for a wiring harness  40 . All angles should be 90 degree right angles in the square frame, so that frame components  16 ,  17  and  22  are parallel to each other. This subassembly forming breakaway frame AAA, together with Frame A, constitutes the whole structure for the first embodiment of the Stop Safety Breakaway Arm Extension  100 . 
     Mounting Frame B, as shown in  FIG. 4  is an initial attachment frame for a second embodiment. One version of mounting frame B is made partially of ¾″ and ½″ square steel tubing. 
     Vertical frame members  1  and  2  in Frame B, as shown in  FIG. 4 , are of the same length, being sufficient to allow un-obscured view of the original, operable STOP sign  51 . Frame members  1  and  2  are an adequate size and placement to meet the bus bracket specifications, and the location of these frame members can be modified, if necessary for adaptation to a configuration of a particular STOP sign  51 . 
     Vertical frame member  2  has two additional 9/64″ holes drilled on the inside of the frame to accommodate stabilizing pins  27 . The holes are oversize relative to the pins  27  allowing for an easier release in case of accident, thus encouraging the breakaway action. These holes should be drilled to exactly match up with the stabilizing pins  27  in frame BBB as shown in  FIG. 8 . 
     Horizontal member  3  is of a length to accommodate the correct spacing of the holes in members  1  and  2 . Horizontal member  3  is positioned midway on vertical member  1 . 
     Support tubing  4  is made of ¾″ square steel tubing at least four inches long and is tapered at one end for cosmetic purposes. As with the first embodiment, tubing  4  supports member  5 , which in turn supports ball stud bearing  6  The support member  5  is made of ¾″ steel angle iron and is two inches long. 
     As in the first embodiment, ball stud bearing  6  is made of ½″ thick Lexan 1½″ by 2″, or other suitable bearing material with a ⅜″ spherical indentation as shown in  FIG. 6  to accept the ⅜″ ball stud  34 . 
     Horizontal member  10  is made of ½″ square tubing approximately six inches long. It has a tapered end for cosmetic purposes and provides the upper support. Member  10  has a hole drilled into it for the shear member  28 , which in this application can comprise a nylon bolt. The distance along the member  10  for the drilling of the hole is such that the resistance obtained when shearing is not less than 40 pounds per shear member  28 . In this embodiment the center of the ¼″ hole is three inches from the inside of the corner of the frame. 
     Horizontal lower member  11  is made of ¾″ square steel tubing and has a tapered end for cosmetic purposes. Horizontal member  11  is of a length to provide support beyond the original STOP sign  51 . A hole in the same position and size as mentioned in member  10  is drilled for the same size shear member  28 . This also has an additional stabilizing shear member 5/32″ hole drilled sixteen inches″ from the part tubing  2 . This smaller shear member  28  provides additional rigidity to make sure the supporting member stays beneath the breakaway member that it supports. 
     This frame B is welded and all openings sealed from the weather. All angles are ninety degree right angles in order to correctly support the next frame BBB. The main function of this piece is to provide a permanent initial frame unto which the breakaway frame can be attached. This provides a means of separation should an accident occur. 
     Frame BBB, as shown in  FIG. 8 , is the breakaway frame or arm that is attached to mounting frame B. One configuration of this is made of aluminum tubing to reduce weight. As configured this weighs under 6 pounds. 
     Vertical frame member  16  is made of ¼″×¾″ flat aluminum. It is drilled to accept ¼″ stabilizing pins which extend into frame B in the member  2  as shown in  FIG. 4 . They are tapered to easier accommodate release if an accident would occur; thus releasing the frame. These holes are within 3″ of the inside corners of the frame. The length is determined by the vertical inside dimension of frame B. This should be about 1/16″ less than the inside dimension of frame A. This is very important as it determines the magnitude of the shear effect. 
     Upper and lower horizontal members  23  and  24  are of equal ¾″ square aluminum tubing approximately eighteen inches in length, and main vertical tubing member  17  is ¾″ square aluminum tubing approximately 19 7/16″ long. 
     Inclined tubing members  19  and  20  are equally sized ¾″ round aluminum tubing about thirty four inches long. 
     Frame components  18  and  21  are made of solid ⅜″ aluminum rod. These are structural members provide additional rigidity, with member  21  located near the middle distance between vertical members  17  and  22 . 
     Outer vertical tubing  22  is made of ¾″ square aluminum tubing  8  ½″ long. It is drilled with two quarter inch holes spaced six inches on center, equal distance from the ends. These holes are for mounting the new STOP sign  31 . 
     Frame BBB is shown  FIG. 8  and its components are welded together and all openings sealed except for that tubing  22  which will have wiring installed. Members  24  and  20  are welded together such that it functions as a continuous conduit for the wiring harness  40 . All angles should be ninety degree right angles in the square frame, and that components  16 ,  17  and  22  are parallel to each other. 
     Frame C is a mounting frame for a third embodiment of this safety arm. One configuration of frame C is made of ¾″ square steel tubing, and shown in  FIG. 5  and the subcomponents of frame C are described as follows. 
     Frame members  12  and  13  are equal in length about twelve inches long. They have a hole drilled into them for the shear member  28 , which currently is a nylon bolt. The distance along the frame member at which the hole is drilled is such that the resistance obtained when shearing is not less than 40 pounds per shear member  28 . In this embodiment the center of the hole is four inches from the outside of the corner of the frame. They have tapered ends at least in part for cosmetic purposes. 
     Tubing members  1  and  2  are identical in this embodiment and they are made of ¾″ square steel tubing and are of a length to provide physical support from the new hinge mechanism  41 , shown in  FIG. 14 , with which mounting frame C is employed. Members  1  and  2  in frame C have holes of an adequate size and placement to conform to the new bus bracket  41 , or modifications thereof. There are two additional 9/64″ holes drilled on the outside of frame member  2  on the frame C to accommodate the stabilizing pins  27 . These are larger than the pins  27  allowing for an easier release in case of accident, thus encouraging the breakaway action. These holes should drilled in exacting placement to match up with the stabilizing pins  27  in Frame CCC, as seen in  FIG. 9 . 
     In frame C, spacer  3  is made of ¾″ square steel tubing and of a length to accommodate the correct spacing of the holes as noted in frame members  1  and  2 . Spacer  3  is located midway to tubing member  1 . 
     The components forming frame C, as shown in  FIG. 5 , are welded together, and should be done so that frame members  1  and  2  are parallel as are horizontal frame members  12  and  13 . All angles should be ninety degree right angles in order to correctly support the breakaway frame CCC. The main function of mounting frame C is to provide a permanent initial frame onto which the breakaway frame CCC can be attached. This provides a means of separation if an accident should occur. 
     Frame CCC, shown in  FIG. 9 , is a breakaway frame or a breakaway extension arm. One configuration of frame CCC is made of aluminum tubing to reduce weight. As configured, frame CCC would weigh under 7 pounds. 
     Vertical tubing  16  is made of ¼″×¾″ flat aluminum. It is drilled to accept ¼″ stabilizing pins  28  which extend into tubing  2  in frame C as shown in  FIG. 5 . They are tapered to easier accommodate release if an accident would occur; thus releasing the frame. These holes are within three inches of the inside corners of the frame C. The length is determined by the vertical inside dimension of frame C. This should be about 1/16″ less than the inside dimension of frame C. This is very important as it determines the magnitude of the shear effect. 
     Frame members  15  on the top and bottom are equal ¾″ square aluminum tubing approximately six inches in length. Vertical frame member  17  is ¾″ square aluminum tubing approximately 21½″″ long. 
     The inclined members  19  and  20  on the top and bottom of the breakaway frame CCC are equal sized ¾″ round aluminum tubing about forty-six inches long. 
     Diagonal frame member  18  and vertical frame member  21  are both made of solid ⅜″ aluminum rod. These are structural members to provide additional rigidity, placing vertical member  21  near the middle distance between vertical frame members  17  and  22   
     Frame member  22  is made of ¾″ square aluminum tubing  8  ½″ long. This is drilled with two ¼″ holes spaced six inches on center, equal distance from the ends. These holes are for mounting the new STOP sign  31 . 
     Components of Frame CCC, shown in  FIG. 9 , are welded together and all openings sealed except for that of member  22  which will have wiring installed. Frame members  15  and  20  are welded together such that it functions as a continuous conduit for the wiring harness  40 . All angles in the square frame C should be ninety degree right angles, and the members  16 ,  17  and  22  be parallel to each other. 
     Anti-Vibration Support Bracket  25  is shown in  FIG. 14B . This bracket  25  is made of ¼″×10″ flat aluminum bent into an U shape with an opening of two inches. The bight of this bracket  25  is secured to the side of the bus and the parallel arms open outward. Bracket  25  thus provides additional support when either of the safety arms  100 ,  200  or  300  is in a retracted position against the side of the bus to provide additional support while traveling between stops. Bracket  25  will prevent rattling and unnecessary wear on the shear members  28 . Two holes are drilled for anchoring with 3/16″ solid pop rivets to a bracket  25  on the bus. 
     Mounting Bracket  26  is shown in  FIG. 14C . This is made of ¼″×12″ aluminum bent to allow for clearance of the bus “ribs” extending longitudinally along the side of a bus. This bracket  26  can be customized to the exact sizes necessary to clear these ribs. Bracket  26  has four holes 3/16″ for mounting on the bus, two at each end. It also has three sets of holes placed equidistant. 
     Stabilizing points  27  are aluminum pins and in either of the embodiments are ⅝″ long ¼″ in diameter with a forty-five degree point on the end. These pins  27  protrude through either member  16  in Frame AAA as shown in  FIG. 7 , or member  16  in Frame BBB shown in  FIG. 8 , or member  16  or Frame CCC shown in  FIG. 9 . This forms a “hinge point” of the frame in case of an accident, while providing stabilization during normal use. The taper on the ends provide quick release should a bus equipped with either of the safety arms  100 ,  200  or  300  be involved in an accident caused by a motorist attempting to pass a stopped school bus with all warning signals deployed. 
     Shear member  28  are made of ¼″ nylon bolts two inches in length. While having exceptional tensile strength they allow for shearing at approximately 40 pounds when positioned three inches from the stabilizing points. These shear pins  28  provide the main strength for preventing breakaway as described for Frame AAA, Frame BBB or Frame CCC. Nylon nuts are also to be used along with Locktight or equivalent. Alternative materials can be used. This would depend on the conditions anticipated, as in rough rural gravel roads, or a plastic frame. Any suitable material that provides the desired effect, including spring loaded mechanisms, tapered pins, may be used. 
     Cover Support Plate  29  is shown in  FIG. 13 . This plate  29  is made of ⅛″×¾″ Aluminum flat stock. Plate  29  is used to secure the new STOP sign  31  to frame member  22  for the embodiments of Frame AAA, Frame BBB or Frame CCC. This is secured by bolts going through all three pieces. This acts like a large washer and provides more stability to the new sign  31 . 
     Lights  30  can be incandescent, LED, or other light sources. Not only are there numerous types, there are equally many shapes and sizes. In the preferred embodiments, an LED light source currently in use with the North Carolina bus system with 10 individual diodes making up the red lens is employed. These provide an extremely bright light that can be flashed. Preferably the brightest light available at the time of manufacture should be employed. The lights  30  were attached with 8-32 stainless bolts of the correct length to hold both the front and rear lights together with stainless nuts and the use of Locktight or equivalent. 
     STOP sign  31  is a double sided STOP sign with 3M finish per National School Bus specifications, Federal Safety Standard 571-131. This regulation could change, and the appropriate sign should be used to meet the current standards as time goes on. 
     Support  32 , shown for example in  FIG. 13 , provides support for the retraction device  35 . Support  32  is made of 5/16″ square solid steel key stock two inches long. It is threaded ½″ on one end for 5/16″-24 thread. The other end is rounded for ⅝″ to 5/16″ diameter for welding into frame A, B or C. 
     Lower bearing support  33 , also shown in  FIG. 13  is made of 2″ angle iron eight inches long that has been drilled with a ⅜″ hole near the center to be at 1¼″ from the outside of the angle iron. This support  33  also has four 3/16″ holes in the opposite side angle for attaching to the bus with 3/16″ solid pop rivets or other suitable fastener. 
     A ⅜″ ball stud and nut  34  is attached to the support  33 . Use of Locktight or equivalent is recommended. 
     Retraction device  35  is a mechanical means of providing flexible support for the whole frame, including both the mounting frames and the breakaway frame, while also enhancing the retraction of the sign against the side of the bus when traveling. Retraction device  35  is an internal winding spring with cable on the outside of a drum that is weatherproof. This could be accomplished with any similar device providing support as well as encouraging closure to the side of the bus. As configured this is one inch thick and 3⅜″ in diameter, model PR325B as manufactured by John Evans Sons. This has a ¾″ brass hinge pop riveted to it, which would be mounted to the bus with two 3/16″ pop rivets. 
     Cushion stop  36 , shown in  FIG. 14A  prevents the sign and lights from hitting the side of the bus. Cushion stop  36  should be placed on the bus at the midpoint of where the stop sign would engage the bus. 
     Small Shear Member  37  is shown in  FIG. 11 . This small shear member  37  is made of an 8-32 nylon bolt, one inch long. This shear member  37  keeps tubing  24  on Frame BBB attached to tubing  11  on Frame B, and in alignment during use to prevent distortion of the aluminum Frame BBB. 
     Male plug  38  male electrical connector suitable for 3 wire 22 gauge and is part of. the wiring harness  40 . 
     Female receptacle  39  is a female connector suitable for 3 wire 22 gauge and is adhered to the frame of A, B or C. This is included in the wiring harness  40 . 
     Wiring Harness  40  is shown in  FIG. 15  and is twenty two gauge, 3 wire cable, preferably UV resistant. This harness  40  connects to the current bus harness with a common splice connector used in automotive for wiring trailer hookups. Liquid insulation and black electrical tape is used to prevent weather damage to the wiring. From there it is connected to a female 3 wire connector (not shown), which in turn plugs into a male 3 wire connector (not shown) and runs inside one of the embodiments Frame AAA, BBB or CCC. This then continues and comes out at frame member  22  of and connects to the lights  30 . 
     Appropriate attachment fasteners are used to hold Frame A or Frame B to the original bus hinge plate (or optional new larger bus hinge plate). In some instances bolts replace the original bolts holding the sign and will now hold the items in this order (starting from the rear), bus hinge plate, original STOP sign, Frame A, B or C. 
     Sign support bolts in the form of ¼″-20 stainless steel fasteners will hold the new, distally positioned STOP sign  31  onto part  22  of either Frame AAA, BBB or CCC. In each case with the stainless nuts or bolts, Locktight or equivalent is to be used. 
     Recommended hardware supplies include Locktight or equivelent for threads, ten 3/16″ aluminum pop rivets, black electrical 600 volt rated tape, three wire automotive low voltage connectors, white lithium grease, epoxy for holding appropriate materials together. 
     All framing is to be thoroughly cleaned, then primed and painted to the specifications of the purchaser. 
     A piece of ¾″ reflective tape eight inches long is used to cover member  2  in either frame where it covers the original stop sign RED at the point of connecting the initial frame. 
     The following is a description of the installation of the preferred embodiment shown in  FIGS. 3 ,  4  and  5  of this invention. The majority of the assembly is already done, so the installation should take only 15 to 30 minutes with 2 persons for the first one, and probably only 15 minutes each for additional installations on other buses. 
     Tools needed include Vise grip pliers, Utility knife, Electrical tester to show 12 volts DC, and two 7/16″ combination wrenches, 
     Start by removing the initial frame and break-off frames from their packaging. 
     Find the package of hardware and supplies. Open the hardware package and compare to list of items required as noted in parts list shown in  FIG. 16 . 
     On the bus, extend the current bus sign arm to the open position. 
     With stop arm in this position, remove supporting bolts or nuts of current sign, having someone support the current sign and wiring. 
     Mount the initial or mounting frame A to the existing stop arm hinge using the hardware provided. There are four points of attachment to secure this frame in place. At this time, beginning with the hinge plate and consecutively located are the bus mounted bracket, then the original stop sign, then the new steel frame installed in that order with the nuts to the outside. 
     At this point, test the electrical wiring of the bus sign by slicing through the insulating cable cover a distance of about 2 inches, being careful not to cut into the individual wire coverings. Do this about midway between the wires leaving the hinge enclosure and the point at which the wiring enters the bus wall, but slightly closer to the bus wall then the sign hinge. Attach one of the snap-on splice connectors to each of the 3 wires. Determine which one of these is the ground wire. The positive sides should show a reading, the ground one will not. 
     Now connect the wiring harness  40  to this with the bare wire being the ground, and the Red and Black wires connecting to the other two. Make sure these flash in an alternating pattern to the original stop sign lights, or other configuration as specified by the purchaser. 
     The lower bearing assembly consisting of a bracket  33  and ball stud  34  is attached to the bus with four 3/16″ solid aluminum pop rivets or other suitable fastener. This is attached after the initial frame A or B is mounted such that the alignment to the existing bearings is exact. This bearing should have a slight upward thrust and shimmed from the side of the bus if necessary. 
     The retraction device should be pre-tensioned to approximately 8 lbs. pull when closed, and attached to the bus approximately 8″ to the rear of the bus from the hinge point of the arm, at nearly the same level as the device itself. 
     Place the Aluminum Safety frame AAA, BBB or CCC as appropriate into the steel frame with the STOP wording on the sign facing up for correct reading. 
     Hold the extension frame in very tight to the attached frame, insert the shear member into the upper shear hole first and then another shear member into the lower hole. Put Locktight or equivalent on the threads of these nylon (or other) bolts and attach nuts onto each bolt and tighten ½ turn past finger tight. 
     If installing mounting frame B, put Locktight or equivalent on the threads of the small shear member and insert into place. Note that this does not go all the way through, and has no nut, it is held in by the Locktight or equivalent. 
     Insert male electrical plug into female socket on initial permanent frame A, B or C. This will not “click in” as you would expect, as it is supposed to disengage if hit by a vehicle. 
     Next test to see if the lights are working properly. 
     Use liquid electrical wire insulation and black electrical tape to seal wire connections at bus from the elements. Use white lithium grease on the outside of the plug in connection between the frames as a weather sealant. 
     The embodiments depicted herein are representative examples of this invention. One of ordinary skill in the art would recognize that modifications would be apparent without departing from the scope of this invention.