Abstract:
A linearly actuated lightbar system elevates an emergency lightbar several feet above the cab or other highest point of a vehicle to provide the earliest possible notification to other drivers as to the presence of a service or emergency vehicle, and to the possible existence of a dangerous situation that requires other drivers to slow down and be more attentive. By raising the lightbar well-above the cab of the vehicle, conditions such as obstructions and topographic characteristics can be overcome that might otherwise delay such notification. The lightbar can then be lowered back to a more typical height for safe travel once the vehicle is ready to leave. A linear actuator is provided to raise and lower the lightbar that can be hydraulic, pneumatic, or mechanical. The system can be coupled to a frame for rigidly coupling the system to the bed, or other stable structure of the vehicle.

Description:
FIELD OF THE INVENTION 
       [0001]    This application relates generally to warning/emergency lighting for vehicles, and in particular to vehicle lightbars. 
       BACKGROUND OF THE INVENTION 
       [0002]    Emergency and service response vehicles such as police vehicles, fire engine trucks, ambulances, tow trucks, and the like, are regularly dispatched to render aid in various accidents and traffic situations. These situations often require the emergency and service vehicles to stop in or very near roadways, over which other vehicles are traveling at high rates of speed and/or where visibility of stopped vehicles is often impaired. Such necessary slowdowns for roadway emergencies or other problems can often lead to additional accidents when the regular flow of traffic is interrupted. Indeed, many roadway service and emergency workers, such as tow truck or wrecker drivers, highway workers, police officers, firemen, and medical personnel, are injured or killed each year by unaware motorists, or motorists who did not receive sufficient advance warning of the dangerous conditions ahead. 
         [0003]    Thus, it is essential that such vehicles identify their presence to other motorists as soon as possible. The earlier motorists become aware of a potential danger or hazard in the roadway ahead, the sooner the motorist can reduce speed and increase their attentiveness. To announce their presence and to warn others of an existing hazard or emergency, emergency vehicles typically employ emergency lights of various configurations to warn motorists of the danger and to indicate the need for traffic to slow down and/or to direct traffic away from the situation. One commonly employed light configuration for emergency and service vehicles is in the form of a lightbar. Lightbars come in many different designs and colors. Regardless of the type of vehicle or the agency for which it has been dispatched, the common purpose of their emergency lighting systems is to provide the earliest possible visual notice to other drivers of the presence of the vehicle and/or the existence of a potentially dangerous emergency situation. 
         [0004]    Notwithstanding the foregoing goal, the ability to perceive common configurations of emergency vehicle lighting at the earliest possible moment can often be thwarted by the topographic features of the surrounding terrain as well as obstacles in or around roadways. For example, if the terrain is hilly and the emergency is one that lies on the downward side of the top of a hill, a driver climbing the front side of that hill may not see the emergency vehicle lighting until the driver has crested the hill at highway speed. This can severely limit the driver&#39;s ability to react to avoid the danger. Obstacles such as overpasses, bridges, signs, berms and the like can also obscure a driver&#39;s view of the lights until the driver&#39;s ability to properly react has been severely impaired. In fact, some emergency vehicles can partially or completely obstruct their own emergency lights when being operated for their intended purpose. For example, when a tow truck picks up a vehicle on a roadway, the lightbar on the tow truck can often be obscured to motorists approaching the tow truck from behind by the vehicle being loaded or towed. 
         [0005]    Typically, externally mounted lightbar installations are configured and integrated with a vehicle to be reasonably aerodynamic. Thus, they are typically mounted close to, if not directly in contact with, the roof of the vehicle&#39;s cab or its highest point of extension. Permanently installing the light bars at a position that is higher above the cab of the emergency vehicle is not a practical solution because the higher the lights are extended, the more prone they will be to being ripped from the vehicle by high wind speeds, except at the slowest of vehicular speeds. Even if such elevated assemblies could be reinforced to remain coupled to the roof notwithstanding shearing forces applied to the lightbar while moving through the air at practical driving speeds, a reinforced elevated lightbar would add an unacceptable element of vehicular instability. 
       SUMMARY OF THE INVENTION 
       [0006]    A linearly actuated elevatable/lowerable lightbar system for vehicles allows a lightbar assembly, capable of providing emergency and/or warning lights for emergency or other vehicles often required to be parked in or near highways, to be elevated well-above the height at which lightbars are conventionally mounted. This increases the visibility of the warning lights to permit other travelers on a highway to become aware of the presence of an emergency or otherwise hazardous condition much sooner than otherwise, thereby increasing the time the travelers have to slow down and become more cautious and aware of the situation. The system then permits the lightbar assembly to be lowered back to a more conventional height so as to reduce air resistance and thereby enable safe travel at highway speeds. 
         [0007]    One general aspect of the invention is a linearly actuated elevatable/lowerable lightbar system for vehicles. The system includes: a lightbar assembly; a linear actuating means for elevating the light bar assembly, and for lowering the light bar assembly once elevated. The linear actuating means includes: at least one rod having a first end coupled to the light bar assembly, and having a second end; and a controlling means for exerting an elevating force on the second end of the at least one rod to elevate the at least one rod and the lightbar assembly coupled thereto, the controlling means being further for removing the elevating force so as to lower the at least one rod and thereby lower the light bar assembly coupled thereto. 
         [0008]    In some embodiments, the system further includes: a frame for rigidly supporting the lightbar system at a first end of the frame, the frame capable of being supportably secured to a vehicle at a second end of the frame. In some embodiments, the frame has a base at the second end that is capable of being secured to a bed of the vehicle. 
         [0009]    In some embodiments, the linear actuating means is a fluid actuator. In some further embodiments, the fluid actuator includes a hydraulic cylinder, and the controlling means includes a hydraulic pump. In some further embodiments, the fluid actuator is a pneumatic cylinder and the controlling means includes an air compressor. In some further embodiments, the fluid actuator is a double action actuator. In some further embodiments, the system further includes a contact sensor to indicate whether the lightbar assembly is in an elevated position. 
         [0010]    In some embodiments, the linear actuating means is a mechanical actuator. In some further embodiments, the mechanical actuator is a set screw and the controlling means includes an electric motor. 
         [0011]    Another general aspect of the invention is a linearly actuated elevatable/lowerable lightbar system for vehicles, where the system includes: a lightbar assembly; a fluid actuator capable of elevating and lowering the light bar assembly, the fluid actuator having at least one rod having a first end coupled to the light bar assembly, and having a second end; a fluid controller capable of exerting an elevating force on the second end of the at least one rod to elevate the at least one rod and the lightbar assembly attached thereto, the fluid controller being further capable of removing the extending force to lower the at least one rod so as to lower the light bar assembly once extended; and a frame for rigidly supporting the lightbar system attached at a first end of the frame, the frame having a second end capable of being supportably secured to a vehicle. 
         [0012]    In some embodiments, the second end of the frame has a base that is capable of being secured to a bed of the vehicle. 
         [0013]    In some embodiments, the fluid actuator is a hydraulic cylinder and the fluid controller includes a hydraulic pump. 
         [0014]    In some embodiments, the fluid actuator is a double acting hydraulic cylinder. 
         [0015]    In some embodiments, the system further includes a contact sensor to indicate whether the lightbar assembly is in an elevated position. In further embodiments, the system also includes a control panel for controlling how far the lightbar assembly is elevated, and for controlling functioning of the lightbar assembly. 
         [0016]    In some embodiments, the system also includes an operator warning indicator located in the control panel that receives a signal from the contact sensor when the lightbar is in an elevated position. 
         [0017]    In some embodiments, the frame supportably couples the lightbar assembly to at least one vehicle frame rail. 
         [0018]    In some embodiments, the frame is configured to mount the lightbar assembly between the cab and the bed of a vehicle. 
         [0019]    In some embodiments, the system also includes a mechanical actuator coupled to the lightbar assembly that can be used to raise and lower the lightbar assembly if the fluid actuator and/or the fluid controller fails. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The following description can be better understood in light of Figures, in which: 
           [0021]      FIG. 1  is an illustration of an embodiment of a elevatable lightbar assembly and linear actuator; 
           [0022]      FIG. 2  is an illustration of the embodiment of a elevatable lightbar of  FIG. 1  mounted on a support frame; 
           [0023]      FIG. 3A  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large tow truck/wrecker, the view being from the rear of the tow truck/wrecker with the light bar elevated; 
           [0024]      FIG. 3B  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large tow truck/wrecker, the view being from the rear of the tow truck/wrecker with the light bar fully lowered; 
           [0025]      FIG. 3C  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large tow truck/wrecker, the view being from the side of the tow truck/wrecker and with the light bar elevated; 
           [0026]      FIG. 3D  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large tow truck/wrecker, the view being from the side of the tow truck/wrecker with the light bar fully lowered; 
           [0027]      FIG. 4A  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large flatbed wrecker, the view being from the side of the wrecker and with the light bar elevated; 
           [0028]      FIG. 4B  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted on a large flatbed wrecker, the view being from the side of the wrecker with the light bar fully lowered; 
           [0029]      FIG. 5A  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted within the cab of a pickup truck, the view being from behind the pickup truck and with the light bar elevated; and 
           [0030]      FIG. 5B  is an illustration of the embodiment of the elevatable lightbar and support frame of  FIG. 2  mounted within the cab of a pickup truck, the view being from behind the pickup truck and with the light bar lowered. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    An illustration of an embodiment of the linearly actuated elevatable lightbar system  100  of the invention is shown in  FIG. 1 . In an embodiment, an external mount lightbar assembly  104  can be elevated to a height well-above the cab of a vehicle (not shown) while the vehicle is relatively stationary. The elevation of the lightbar assembly  104  is accomplished using a linear actuating means  106 . The lightbar assembly  104  can, from the extended position, be lowered back to a standard height (typically close to or flush with the top of the cab) using the linear actuating means  106  so that the vehicle may once again travel safely at highway speeds. The linear actuating means  106  can be fluid actuated, such as hydraulically or pneumatically. In the alternative, the linear actuating means  106  can be mechanically actuated, such as for example by manipulating a set screw either by way of an electric motor or manually, or through use of a scissor-lift arrangement. Details of various embodiments of the linear actuating means  106  will be discussed in further detail below. 
         [0032]    Those of skill in the art will recognize that there are a myriad of commercially available external mount light bar assemblies  104  of various designs on the market. The present invention can be easily adapted to function with virtually any of such commercially available designs. As illustrated by  FIG. 1 , a light bar assembly  104  may include a lightbar support mount housing  110  that supports and/or houses one or more light bars (e.g.  114 ,  116 ). Light bars  114 ,  116  can contain any number of lights of various colors, and they can be of various types including incandescent, halogen, and Light Emitting Diodes (LEDs). They can be made to create patterns of light using several techniques, including various flashing patterns, or the lights can be mechanically manipulated by rotating, rolling or otherwise moving the lights. 
         [0033]    In an embodiment, a lightbar cable  112  is shown coupling an electrical source  150  to lightbars  114 ,  116  so as to supply the necessary power to illuminate and operate the lightbars  114 ,  116 . Electrical source  150  can be a vehicle&#39;s battery coupled through the vehicle&#39;s electrical system, or it can be a separate power supply (such as a battery) dedicated to supplying power to the lightbars  114 ,  116 . Lightbar support housing  110  may also provide a junction box or connection point (not shown) to provide a single connection between lightbar connection cable  112  and lightbars  114 ,  116 , and any other devices mounted to lightbar support housing  110 . Some lightbar designs do not require an external lightbar connection cable  112  to an external power source  150  in the manner illustrated in  FIG. 1 . Lightbars using light-emitting diodes (LED), for example, require very little power to operate and can be supplied with power using, for example, a lithium battery that is small enough to be proximately located with the lightbars  114 ,  116  themselves, such as within the support mount housing  110 . 
         [0034]    In a fluid actuated embodiment of linear actuating means  106 , lightbar support housing  110  is coupled to and supported by two fluid actuators  120 ,  130 , which can be either hydraulic or pneumatic actuators such as single or double acting cylinders. Each of fluid actuators  120 ,  130  can include a rod ( 122 ,  132 ), having one end coupled to the lightbar support housing  110  and the other end disposed within a cylinder ( 124 ,  134 ). Fluid actuators  120 ,  130  may be formed of steel, aluminum, or any other material suitable to raise and support lightbar assembly  104  and all of its components, including lightbar support housing  110 , lightbars  114 ,  116  and any other objects mounted thereto. Moreover, those of skill in the art will recognize that fluid actuators  120 ,  130  can be scaled in diameter and length as appropriate in relation to the size and weight of the lightbar assembly that is to be actuated and the height to be attained. In some embodiments, a single fluid actuator may be used to raise and lower lightbar assembly  104 . In such embodiments, one or more telescoping supports may be provided to help keep lightbar assembly  104  in a desired orientation. 
         [0035]    Fluid controller  140  may include a hydraulic pump (for providing a liquid such as oil to the fluid actuators  120 ,  130 ) or a pneumatic air compressor (for providing compressed air to the fluid actuators  120 ,  130 ). As will be known to those of skill in the art, double acting fluid actuators  120 ,  130  may be operably connected to fluid controller  140  with fluid lines  121   a,b  and  131   a,b  respectively to control a double acting cylinder. To raise the lightbar assembly, lines  121   a ,  131   a  supply fluid under pressure from fluid controller  140  to the cylinders  124 ,  134  respectively, thereby creating a force at the end of a piston disposed within the cylinders (not shown) by which to extend rods  122 ,  132  upwardly in the cylinder. Likewise, to lower the lightbar assembly, fluid controller  140  supplies fluid under pressure to the opposite end of the piston through lines  121   b ,  131   b  to create a downward force by which the piston is forced back down inside the cylinders  124 ,  134  thereby forcing the fluid at the opposite end of the piston back through lines  121   a ,  131   a  to fluid controller  140  and allowing rods  122 ,  132  to retract. This fluid will be forced back through lines  121   b ,  131   b  to fluid controller  140  when the lightbar assembly  104  is raised again. 
         [0036]    Those of skill in the art will recognize that when the lightbar assembly  104  has sufficient weight, a single acting cylinder can be used where by the fluid controller  140  can simply remove the pressure on the fluid supplied through lines  121   a ,  131   a , and the weight of the lightbar assembly  104  will force the fluid from the cylinders  124 ,  134 , thereby allowing the rods  122 ,  132  to retract and the lightbar assembly  104  to be lowered. 
         [0037]    Fluid controller  140  may be located anywhere on a vehicle, and may even be a fluid controller for a hydraulic or pneumatic system already installed on the vehicle for other purposes. For example, a backhoe working on a road project may have a lightbar to warn workers or motorists of the backhoe&#39;s presence. Fluid actuators  120 ,  130  may be connected to existing auxiliary hydraulic connections used to control the shovel on the backhoe and can be controlled using the built-in auxiliary controls of the backhoe. 
         [0038]    As previously mentioned, the linear actuating means  106  can include linear actuators  120 ,  130  that are raised and lowered mechanically, for example, by way of a threaded set screw (not shown) that when rotated in one direction applies force to the base of the rods  122 ,  132  as the screw extends in one direction, which in turn extends the rods  122 ,  132  upwardly thereby raising the lightbar assembly attached thereto. When rotated in the opposite direction, the set screw retracts and thus permits the rods  122 ,  132  to retreat, thereby lowering the light bar assembly. The screw can be turned using an electric motor driven by power source and controller  150 , or it can be manually turned using, for example, a hand crank that is coupled thereto. 
         [0039]    In other embodiments of the actuating means  106 , such a mechanical actuation design can also be incorporated as part of an embodiment that includes a fluid actuation technique to offer redundancy should the fluid actuation means of the system fail. The mechanical system could still be operated manually to raise and lower the lightbar assembly in the event of a total fluid system failure. 
         [0040]    Power source and controller  150  may be operably coupled to fluid controller  140 , control panel  160 , lightbars  114 ,  116 , and any other electrically controlled devices of the system of the invention. Power source and controller  150  may be located in any convenient location on a vehicle having elevatable lightbar assembly  100  installed thereon. Electrical controller  150  may also be located within control panel  160  in some embodiments. 
         [0041]    In an embodiment, control panel  160  may include a vertical height control switch  162 , lightbar operation switch  164 , and elevation warning light  166 . Control panel  160  may be located in a cab of a vehicle having an embodiment of the elevatable lightbar assembly  100  installed on the vehicle, or it may be located on a support frame  200  in other embodiments. Lightbar operation switch  164  may be multiple switches, or may have multiple settings, depending on the type of lightbar used. 
         [0042]    Vertical height control switch  162  may be used to operate fluid controller  140  to extend rods  122 ,  132  out of cylinders  124 ,  134  and vertically extend lightbar assembly  104  and its lightbars  114 ,  116  to a desired height. In some embodiments, a single touch of vertical height control switch  162  will automatically extend rods  122 ,  132  to a predetermined operating height. For example, there might be a predetermined medium extension level and/or a maximum extension level. In other embodiments, the height may be controlled by holding vertical height control switch  162  until the desired height of lightbar assembly  104  is achieved, thereby permitting a degree of extension between fully lowered and a predetermined maximum elevation. Internal sensors (not shown) may be used in conjunction with fluid controller  140  to ensure that the maximum level of elevation is not exceeded. 
         [0043]    Elevation warning light  166  may be operably coupled to a contact sensor  170  to provide a visual warning and reminder that lightbar assembly  104  is in an elevated position and thus the vehicle should not be driven at any other than very slow speeds if at all. For example, lightbar assembly  104  may be elevated to such a height that it may be damaged or destroyed if the vehicle exceeds a certain speed. Similarly, lightbar assembly  104  may be elevated too high for overpasses, power lines, or trees in certain areas, thus requiring lightbar assembly  104  to be lowered to cab height before driving or maneuvering the vehicle. Contact sensor  170  may send a signal to elevation warning light  166  when the lightbar assembly is raised above cab height and is no longer in contact with the tops of the cylinders  124 ,  134 . In some embodiments, contact sensor  170  may be a position sensor, limit switch, etc. Similarly, elevation warning light  166  may be a position indicator capable of conveying the extent to which lightbar assembly  104  has been raised above the cab of the vehicle. Other warning mechanisms may also be employed, including audio warnings, to remind the operator of the vehicle that the lightbar assembly  104  has not yet been fully lowered. 
         [0044]      FIG. 2A  illustrates a front view of an embodiment  200  of the linearly actuated elevatable lightbar system  100  of the invention as shown in  FIG. 1 , installed on a support frame  201 . In an embodiment, support frame  201  includes two vertical members  204 ,  206  that support the cylinders  124 ,  134  of fluid actuators  130 ,  134  respectively, which in turn provides structural support for the lightbar assembly  104 . To provide additional support against rotation of the system  100 , the frame  201  includes a base  202  with cross-members  208 ,  210  as illustrated  FIG. 2B , which shows a side view of the embodiment  200  of  FIG. 2A . In an embodiment, fluid controller  140  and power source  150  are supported by base  202 . As previously mentioned, they can be located anywhere on the vehicle that reasonably permits them to be coupled to the fluid actuators  130 ,  134 . As illustrated, cylinders  124 ,  134  can be disposed and secured inside of the vertical members  204 ,  206  to ensure stability of the system, particularly when in the fully elevated position. 
         [0045]      FIGS. 3A and 3B  illustrate a view from the rear of a large tow truck/wrecker  300  having the embodiment  200  as illustrated in  FIGS. 2A and 2B  installed thereon, with the system in an raised state and lowered state respectively. A window is opened in the towing infrastructure to reveal the details of the embodiment  200  so that they can be more easily seen. The frame  201  of embodiment  200  can be bolted to the truck/wrecker  300  wherever convenient. For example, the base  202  can be bolted to the same bed of the truck/wrecker  300  that is used to support the towing apparatus. The embodiment  200  can be located directly behind the cab such as between the cab and the towing apparatus. To further ensure stability of the system  200 , the vertical members  204 ,  206  of frame  201  could be bolted, screwed or otherwise secured to a vertical structure of the tow truck/wrecker  300 , such as the cab or for example, a vertical structure that is used to isolate the towing equipment from the cab of the tow truck/wrecker  300 . Those of skill in the art will recognize that the embodiment of the system  200 , including frame  201 , can be installed anywhere on the bed of the truck/wrecker  300  as is convenient and space allows. 
         [0046]      FIGS. 3C and 3D  illustrate tow truck/wrecker  300  from the side with the system  200  in the fully elevated and fully lowered positions respectfully. 
         [0047]      FIGS. 4A and 4B  illustrate the system  200 , in elevated and lowered states respectively, installed on a flatbed style tow truck  400 . In this illustration, the base  202  of frame  201  is coupled to the stationary under-bed or rails (not shown in detail) that are part of the frame or chassis of the truck (not shown in detail), and not to the bed that is capable of being inclined to the ground to receive the vehicle to be towed. 
         [0048]    In some embodiments, cylinders  124 ,  134  of actuators  120 ,  130  may be mounted directly to the frame, chassis or other sturdy portion of a vehicle  10  to allow for secure elevation of lightbar assembly  104 . In other embodiments, such as is shown in  FIGS. 5A and 5B , cylinders  124 ,  134  of actuators  120 ,  130  are secured internally to pickup truck  500 . In such embodiments, cylinders  124 ,  134  of actuators  120 ,  130  may be mounted directly to the back-wall of an extended cab, or may be mounted using a smaller support frame (not shown) coupled to the floor of the cab, so that the rods  122 ,  132  can extend out through the roof of the cab as illustrated. 
         [0049]    As previously mentioned, in various embodiments, lightbar assembly  104  may be elevated from a few inches to ten feet or more above the cab of a vehicle having an elevatable lightbar system  100  installed therein. The range of elevation can be varied depending upon the particular application. The size and weight of lightbar assembly  104  (including lightbars  114 ,  116  and any other devices mounted thereto), and the desired maximum elevation of lightbar assembly  104  will dictate the appropriate size and type of the fluid actuators to be used. The fluid actuators  120 ,  130  shown in  FIGS. 1-5  are single-stage hydraulic cylinders. In some embodiments, fluid actuators may be multi-stage hydraulic or pneumatic cylinders, depending on the type of and size of the vehicle, the desired elevation height, and the overall application. For example, as the vehicle gets larger, the lightbar assembly used for that vehicle may get larger, and thus the size and types of fluid actuators and the size of the frame used to support them may be scaled accordingly. 
         [0050]    In addition to any previously indicated modification, numerous other variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of this description, and appended claims are intended to cover such modifications and arrangements.