Abstract:
A tip up light bar assembly includes front and rear light bars pivotally supported above transversely opposed end assemblies joined by connector bars to form a rigid support structure. Each light bar is built on a rigid substrate having a uniform cross section. Longitudinally extending features of the rigid substrate provide locations for mounting light sources, electronic assemblies and lenses which, together with gaskets, define a weather-resistant enclosure surrounding the light sources and electronic assemblies. The light bars pivot at transversely opposed ends to a vertical position in which the light sources are elevated above traffic. Each end assembly includes a base plate, a pivotally mounted pivot plate. A gas spring reduces the dead weight of the light bar while a limit strap controls angular movement of the light bar relative to the base plate to approximately 90°. A motor-drive actuator exerts outward force on the pivot plates to move the light bars between a horizontal and vertical position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to vehicular warning light systems intended primarily for installation on service vehicles operating on public roads. More particularly, the invention is directed to a vehicular light bar which can be raised from a horizontal to a vertical position to elevate warning lights on the light bar above traffic to give long-range notification of an obstruction or accident in the roadway. 
     2. Description of the Related Art 
     Warning light assemblies in the form of light bars mounted on emergency vehicles are well known in the art. The modern trend is toward compact, low profile, self-contained light bar assemblies. Compact self-contained light bar assemblies simplify installation and maintenance while improving the aerodynamic efficiency of vehicles so equipped. Self-contained light bar assemblies include power supplies and control circuitry necessary for actuation and coordination of the various warning lights included in the assembly. Typically, a light bar extends across the width of the vehicle to provide a laterally extended light array including various flashers, spotlights and/or stroboscopic light sources to draw the attention of other vehicles on the roadway. Such light bar assemblies tend to include light sources directed to the front and rear of the vehicle and may include light sources directed to the sides of the vehicle or rotating light sources. Warning light bars are typically rigidly fixed to the roof or highest point of the vehicle for increased visibility. 
     It is also known in the art to provide auxiliary vehicle warning lights on arms movable between a horizontal and vertical position. Lollypop-type warning lights facing the front and rear of the vehicle are arranged along the arms such that when the arms are raised to a vertical position, the warning lights are elevated above traffic to provide advance warning to those approaching the scene of an accident or obstruction. These known auxiliary warning light systems cannot function as a replacement for a typical light bar assembly because they are typically of a configuration dedicated to an elevated warning function. Thus, known vehicular hazard light systems movable between horizontal and elevated position must be provided in addition to the rigidly mounted horizontal light bar typically associated with police and fire emergency vehicles. 
     There is a need in the art for a light bar system that will fulfill both the conventional warning light bar function as well as provide an alternative elevated advance warning function. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a new and improved tip up light bar assembly which may replace a fixed horizontal light bar on service vehicles and provide a second, elevated warning light position. 
     Another object of the present invention is to provide a new and improved tip up light bar assembly of efficient manufacture. 
     A further object of the present invention is to provide a new and improved tip up light bar assembly having a flexible user-selectable configuration which can also function as a horizontal light bar. 
     These and other objects of the present invention are achieved by pivotally supporting front and rear light bars above transversely opposed end assemblies joined by connector bars to form a rigid support structure. Each light bar is built on a rigid substrate having a uniform cross section. Longitudinally extending features of the rigid substrate provide locations for mounting light sources, electronic assemblies and various lenses. The lenses, together with gaskets, define a weather-resistant enclosure surrounding the light sources and electronic assemblies. 
     The light bars pivot at transversely opposed ends to a vertical position in which the light sources are elevated above traffic. End assemblies pivotally support the hinge end of each light bar and provide a bumper for supporting the light bar free end in the horizontal position. Each end assembly includes a base plate, a pivotally mounted pivot plate, gas spring and limit strap. The gas spring reduces the dead weight of the light bar while the limit strap controls angular movement of the light bar relative to the base plate to approximately 90°. A motor-driven actuator exerts outward force on the pivot plates to move the light bars between a horizontal and a vertical position. 
     The tip up light bar assembly may supplement or replace standard fixed horizontal light bars on service vehicles. An optional traffic advisor including directional indicators may be fixed to the rear of the tip up light bar assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an oblique front view of a tip up light bar assembly in accordance with the present invention mounted to an emergency vehicle and shown in the elevated position; 
     FIG. 2 is a detailed view of an end assembly mounting framework and motor driven actuator for the tip up light bar of FIG. 1; 
     FIG. 3 is a rear view of the tip up light bar assembly of FIG. 1 including an optional rear facing traffic advisory; 
     FIG. 4 is an oblique side view of the tip up light bar assembly of FIGS. 1 and 3 shown in the horizontal position; 
     FIG. 5 is a top schematic illustration of the front and rear light bars of the tip up light bar assembly of FIG. 1; 
     FIG. 6 is an exploded perspective view of the end assemblies, framework and motor driven actuator for the tip up light bar assembly of FIG. 1; 
     FIG. 7 is an exploded perspective view of the front light bar of the tip up light bar assembly illustrated in FIG. 1; 
     FIG. 8 is an enlarged detail view of the lower left end portion of the front light bar illustrated in FIG. 7; and 
     FIG. 9 is an enlarged detail view of the upper left end portion of the front light bar illustrated in FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 1-9 wherein like reference numbers refer to like parts throughout the Figures, a tip up light bar assembly in accordance with the present invention includes front and rear light bars which are movable through an arc of 90 between a horizontal position (illustrated in FIG. 4) and a vertical position (illustrated in FIGS.  1  and  3 ). In accordance with the present invention, front and rear light bars  12 ,  14  are secured to opposed end assemblies  18  which are in turn connected by front and rear connecting bars  16 . In a horizontal, or resting position, the light bars  12 ,  14  extend across the width of the vehicle  200  to present an elongated warning light array to approaching vehicles and pedestrians. When discussing the tip up light bar assembly  10  in this specification, the terminology “length” and “longitudinal” will refer to that dimension of the tip up light bar assembly extending across the width of a vehicle. The lateral dimension of the tip up light bar assembly is that dimension directionally corresponding with the length of a vehicle  200 . 
     With reference to FIGS.  5  and  7 - 9 , each light bar  12 ,  14  includes a plurality of light sources  50 ,  52 ,  54  mounted to a rigid substrate  30  and enclosed within a multi-part lens assembly  70 . The lens assembly components include light transmissive end domes  72 .and light transmissive sections  76  as well as opaque sections  74 . Each lens element  72 ,  74 ,  76  includes a lower lip  73  configured to compress a gasket cord  78  into a channel  36  defined by the rigid substrate  30 . Divider gaskets  80  and divider segments  82  separate each lens element  72 ,  74 ,  76 . The divider gaskets  80  each include a groove  81  configured to mate with the end of a lens element  72 ,  74 ,  76  on one side. A channel  83  in the divider segment  82  receives the divider gasket such that when the lens elements, divider gaskets and divider segments are assembled to the rigid substrate  30 , each divider gasket  80  is held in compressed relationship between a lens element and a divider segment  82 . Each divider segment  82  includes a downward projection  85  configured to engage the gasket cord channel  36  defined by the rigid substrate  30 . Together, the gaskets, lens elements and divider segments form a substantially weather tight lens assembly  70  enclosure surrounding the plurality of light sources and any electronic assemblies mounted to the rigid substrate  30 . 
     Each rigid substrate  30  in the illustrated preferred embodiment comprises an extrusion of aluminum alloy. Other materials and methods of manufacture are possible. However, extruding is a particularly efficient method of manufacturing the complex, but uniform cross sectional shape of the rigid substrate  30 . A plurality of channels, each defining a longitudinally extending opening, extend the length of the rigid substrate  30 . Two downwardly facing channels  20  are configured to receive the enlarged head of mounting fasteners  24  which will be used to secure the rigid substrate  30  to a pivot plate as will be discussed below. A gasket channel  36  is defined along the upper outer longitudinal edges of the rigid substrate  30  for receiving the gasket cord  78 . End pieces  26  mount to opposed ends of the rigid substrate  30  to provide a finished appearance for the lateral ends of the light bar. The end pieces  26  extend the gasket channel  36  around the lateral ends so that the gasket channel circumscribes the periphery of the rigid substrate  30 . Fastening hardware passes through the end pieces and into an extruded fastener receptacle  25  in the rigid substrate. 
     The rigid substrate  30  also defines a plurality of rectangular C-shaped mounting channels  22 , two of which face upwardly, and two of which face outwardly along the front and rear longitudinal edges of the rigid substrate. These C-shaped rectangular channels  22  receive plastic screw anchors  28  that expand within the channel  22  when penetrated by an appropriate fastener  29 . Each expanded screw anchor  28  is securely fixed relative to the rigid substrate  30  by the compressed relationship within the C-shaped mounting channel  22 . The channel/screw anchor/fastener arrangement provides a flexible means for securing all of the various components, i.e., light sources, electronic assemblies, and lens elements at selected positions along the rigid substrate  30 . 
     It will be understood by those of skill in the art that the above-described rigid substrate, channel and plastic screw anchor assemblies provide for flexibility in configuring the light bar. Brackets  44  secured to the rigid substrate support pairs of front and rear facing light sources. The light sources and lens components  56  are in turn secured to the brackets by similar screw anchors  28  and fasteners  29 . Each light bar may thus be custom configured to customer specifications. The rigid substrate is machined to provide an opening  32  through which electrical cabling  40  can pass to provide power and control signals to the light sources and electronic assemblies within the enclosure defined by the lens assembly  70 . A grommet  34  protects the cable  40  from chafing. 
     FIG. 5 is a schematic illustration showing the types and relative locations of the light sources for the illustrated preferred embodiment, which should be regarded as representative of numerous possible configurations. The front light bar  12  illustrated in FIGS. 7-9 is illustrated at the bottom of FIG. 5 while the rear light bar  14  is illustrated above. Each light bar  12 ,  14  includes light sources facing the front and rear of the vehicle. The illustrated preferred embodiment of the front light bar  12  includes two centrally located, forward-facing halogen lamps  50  and two centrally located, rearward-facing LED light sources  52 . Front and rear-facing stroboscopic light sources  54  are located adjacent the right end and inwardly from the left end of the front light bar  12 . Rear light bar  14  includes the same configuration of two central forward-facing halogen lamps  50  and two rearward facing LED light sources  52 . The location of the four stroboscopic light sources  54  of the rear light bar  14  is a mirror image of the corresponding components of the front light bar  12 . 
     Electrical cabling  40  enters each light bar through opening  32  to carry electrical power and/or control signals into the enclosure defined by the lens assembly  70 . Internal wire harnesses  42  distribute power within the light bar. Generally, vehicle power is delivered to a power supply  48  and then distributed by internal wire harnesses  42  and connectors  46  to the stroboscopic light sources  54 . Power for the LED and halogen light sources  52 ,  50  does not pass through the power supply, but is provided directly from a switched power supply mounted inside the vehicle  200 . It will be understood that the location and types of light sources will typically be dictated by customer specification and are entirely flexible in accordance with the present invention. 
     The front and rear light bars are pivotally supported above an emergency vehicle  200  by laterally opposed end assemblies  18  connected by front and rear connecting bars  16 . With reference to FIGS. 2,  4  and  6 , each end assembly includes a base plate  90 , pivot plate  92 , gas spring  64 , folding limit strap  66 , and associated hardware. In the illustrated preferred embodiment, base plate  90  and pivot plate  92  are castings of aluminum alloy, although other materials and methods of construction are of course possible. The end assemblies  18  are essentially the same and are rotated  180  to support the laterally opposed ends of the front and rear light bars  12 ,  14 . Each base plate  90  includes four mounting points  95  for securing the front and rear connector bars  16 . The mounting points  95  are defined by elevated, reinforced brackets such that the base plate  90  has a cradle-shaped configuration. In the illustrated embodiment, the front and rear connector bars  16  are extrusions of aluminum alloy and are identical. When secured to the base plates  90  by fasteners  98 , the connector bars  16  maintain the base plates in alignment and provide a rigid framework for supporting the pivotally mounted light bars  12 ,  14 . 
     Each base plate  90  defines a pivot point for a pivot plate  92 . The pivot point comprises laterally spaced flanges  94  defining openings through which shouldered fasteners  93  pass to engage plain bearings  91  secured in complementary openings in the pivot plate  92 . The lateral spacing of the pivot flanges  94  enhances the structural rigidity of the pivoting assembly. Webs  97  and ribs reinforce the structural integrity of the pivot plate  92 . The base plate  90  and pivot plate  92  also define locations for mounting opposed ends of a gas spring  64  and limit strap  66 . The gas spring  64  is connected between the base plate  90  and the pivot plate  92  to reduce the dead weight of each light bar and thus assist in raising the light bar from its horizontal position to a vertical or warning position. Ball end studs  62  secured to the base plate and pivot plate are received in end fittings  58  on the gas spring  64 . A two piece folding limit strap  66 , secured to both the base plate and the pivot plate, limits upward angular movement of the pivot plate  92  relative to the base plate  90 . The limit strap  66  is folded when the pivot plate  92  is in a horizontal position and extends to a maximum length when the pivot plate is substantially perpendicular to the mounting plate  90 . 
     Each pivot plate  92  presents a large support surface to which a first or hinge end of each light bar  12 ,  14  is mounted. The illustrated pivot plates include four openings  84  through which the large headed fasteners  24  pass to secure the rigid substrate  30  to each pivot plate  92 . Each pivot plate  92  further defines an opening  86  through which cabling can pass into the light bar  12 ,  14 . Each base plate  90  defines a corresponding cabling opening  88  and a raised location to which is mounted a bumper  68  to support the second end of each light bar  12 ,  14  when the light bars are in the horizontal position. Each pivot plate further defines a location for securing an actuator-mounting stud  96 . A motor driven actuator  60  is connected between the pivot plate-mounted actuator-mounting studs  96  by rigid actuator tubes  61 . The actuator tubes  61  are secured over the actuator studs by snap rings  100 . The motor driven actuator  60  applies equal outward force to both actuator-mounting studs, causing the front and rear bars  12 ,  14  to rise from their horizontal position to the vertical warning position. The actuator mounting stud locations are spaced apart from the pivot plate pivot point  99  to provide mechanical leverage on the light bars  12 , 14 . The gas springs  64  include damping means for smoothing the raising and lowering of the light bars. One end of the motor driven actuator  60  is fixed relative to an actuator mounting stud  96  by a short actuator tube  61 , while the other end of the motor driven actuator comprises a ram from which a long actuator tube  61  extends to connect to the opposed actuator mounting stud  96 . 
     When in the lowered or rest position illustrated in FIG. 4, the tip up light bar assembly  10  may serve as a fully functional emergency vehicle warning light bar. Each light source  50 ,  52 ,  54  includes a reflector and/or lens which defines a direction of light transmission A for the light source (see FIG.  5 ). As can be seen from FIGS. 4 and 5, in the lowered or rest position, the direction of light transmission A for the rear-facing LED light sources  52  of the front light bar  12  must pass through the forward-facing halogen light sources  50 . Thus, when viewed from the front, light emitted by the forward-facing halogen light sources  50  of the rear light bar  14  is substantially blocked by light sources  52 ,  50  mounted to the center of the front light bar  12 . In accordance with a significant aspect of the invention, some of the light sources are arranged in a staggered configuration to permit the rear-facing front light bar strobes  54  to be visible through light transmissive elements of the rear light bar  14 . Correspondingly, the front-facing rear light bar strobes  54  are visible through light transmissive elements of the front light bar  12 . The mirror image front and rear light bars present a symmetrical lighting configuration when raised to the vertical or warning position. 
     FIGS. 3 and 4 illustrate an optional traffic advisory  102  which may be mounted to the rear connector bar. The traffic advisory  102  includes a plurality of yellow caution light sources and laterally spaced directional indicators. The optional traffic advisory  102  permits emergency personnel to direct oncoming traffic toward the left or right of the emergency vehicle so equipped. 
     It will be noted that the illustrated tip up light bar assembly  10  is mounted in an elevated position relative to the roof of an emergency vehicle. This permits continued use of the conventional light bar already fixed to the emergency vehicle  200  (see FIGS.  1 - 4 ). Alternatively, the conventional light bar may be omitted with the tip up light bar assembly  10  mounted more closely to the roof of the emergency vehicle  200 . 
     While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.