Abstract:
A golf cart safety bar device is activated by occupied cart seats operatively installed on the cart frame to swivel about hinges and on spring biases. The safety bar device includes a pair of laterally adjacent driver/passenger seat bottoms each having a front end and a rear end. A weight is installed internally or externally of the cart frame to hold up the seat front at rest until the seating passenger depresses it. The weight means provides an eccentric weight about its own axis of rotation. A safety bar is fixed at one end to the weight means with the opposite end protruding upright at rest in preparation for a passenger to board the cart without a blocking. When passengers sit the safety bars are lowered limiting lateral outward movement of passengers from the cabin. The safety bars block the entrances or exits.

Description:
BACKGROUND OF THE INVENTION 
   A. Field of the Invention 
   The present invention relates to a safety device for vehicles, and more particularly to a safety barrier for passenger carts with an open cabin. 
   B. Description of the Prior Art 
   Along with a growing population of golf players, golf course accidents have become more frequent, especially golf cart accidents. Golf carts can lead to a variety of accidents like passenger falling out of moving golf carts, or cart collisions. Despite their boarding convenience, golf carts are commonly unenclosed and lack proper rider support through rough terrain or steep slope, which can be found in many golf courses today. Because the golf carts are made for club premises and not for street driving, they have been free of safety restraint requirements or protections that make them vulnerable to risks. If a cart path has such steepness, sharpness and narrowness that require a driver to take a sharp turn, chances of serious accidents become high resulting in incurable injuries and even fatalities of the riders. Also, more and more children are playing golf and riding as golf cart passengers on a golf course and the current safety equipment is not well suited for smaller passengers. 
   For the sake of riding comfort, there were suggestions to close the open sides of the golf carts. U.S. Pat. No. 6,293,610 to Howard represents a custom designed door system for golf cart-type street vehicle to modify an open golf cart to a street legal version with an enclosure top. However, a practically simple safety means is not yet available to retrofit in the current cabin design of golf carts. Also, no suggestions have yet been made to provide an automatic safety means for golf carts where the passenger&#39;s weight switches a side safety barrier. 
   Therefore, the object of the present invention is to provide a safety bar barrier for unenclosed vehicles including golf cart, which barrier is activated by a cart seat occupied by the passenger or driver. Another object of the present invention is to provide a safety bar barrier for golf cart having an optional privacy protection in addition to the novel transportation safety. 
   SUMMARY OF THE INVENTION 
   A safety bar device according to the present invention is used for vehicles with an open cabin having a frame unit mounted on motorized wheels. The device comprises (a) at least one swivel seat bottom mounted at its rear end on the frame unit through a number of hinges under a spring bias, (b) a gravity actuator installed to pivot about an axis on the frame unit and provide an eccentric weight for pushing up the seat at an angled posture with its front end raised until it is switched back to a leveled position by the weight of a seating passenger, and (c) an elongated bar generally L-shaped which is fixed at its proximal end to the gravity actuator with the opposite end protruding upright at rest in preparation for the passenger to board the vehicle without an interference until the passenger takes the seat which activates the elongated bar against the bias of the gravity actuator lowering the bar. This limits lateral passenger movement from the cabin of the vehicle to keep passengers in their seats. 
   The vehicle may be a golf cart that is impractical to have a conventional safety restraint for street vehicles. 
   The golf cart seat-activated safety bar device of the present invention includes a pair of laterally adjacent driver/passenger seat bottoms each having a front end and a rear end, which is pivotally connected through a number of hinges to a raised floor of the golf cart frame. Also, a number of leaf springs are disposed next to the hinges to assist in supporting the seat bottoms at a raised position at which the passenger takes a seat. 
   A weight rotor is a primary actuator to hold up the seat front at rest until the seating passenger occupies and depresses it. The rotor is made of a heavy solid material such as metal and has a deep V-shaped notch down to its center of rotation to provide an eccentric weight to a shaft to which the rotor is fixed under the frame floor. 
   The shaft is rotatably supported at its outer end by a metal bracket fixed externally of the cart frame and at its inner end by an interior bracket extending from a wall of the frame. An articulated push bar has a lower leg fixed to the rotor at its bottom end by one or more fasteners. The leg also has a top end connected to an upper arm via an articulated connection. The arm is fixed at its distal end to the bottom surface of the seat bottom by a hinge. 
   An elongated safety bar is generally L-shaped and connected at its proximal end to an auxiliary weight arm, which is in turn attached to the protruding end of the rotor shaft. The remainder of the safety bar protrudes upward at rest in preparation for a passenger to board the cart without a blocking. 
   The safety bar has a length that extends across the cabin at least partially and a certain height above the top surface of the seat bottom to support the torso of a passenger in a rough ride. The safety bar has a bore to grasp the shaft to ensure a non-rotating engagement between them. The bar is lightweight relative to the weight rotor and supportive of the moment of inertia of the torso of a boarding passenger in operation and it may be made of a variety of materials including wood, plastic or aluminum among others. 
   Thus, the safety bar is normally standing upright to clear a way for the passenger to enter the cart without interference. 
   When the passenger enters and the seat bottom is depressed, the push bar is lowered against the weight bias of the rotor and the spring bias. The safety bar is also lowered to a level to limit the lateral outward movements of the passenger from the cabin of the golf cart. The bar at the seat bottom now blocks the entire entrance or exit of that side of the cart to prevent involuntary fallout of the passenger from the seat bottom. 
   When a passenger is off the safety seat, the weight of the rotor and arm prevails to uphold the front end of the seat bottom, which is also supported by the expanding leap springs at the rear end of the same seat bottom. At the same time, this pivotal urge of the arm about its axis maintains the safety bar standing upright to clear a way for the passenger to enter the cart without interference until the passenger occupies the seat which then switches the safety bar down into the operational level. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the golf cart according to prior art omitting its roof and support frame for simplicity. 
       FIG. 2  is a front view of a pair of driver/passenger seats equipped with a safety bar device according to a first embodiment of the present invention showing one side bar at rest contrasted to another in operation. 
       FIG. 3  is a partially broken away perspective view of the seat-activated safety bar device of  FIG. 2  in its upright position about a pivotal shaft at rest. 
       FIG. 4  is a perspective view of the seat-activated safety bar device of  FIG. 3  in operation. 
       FIG. 5  is a perspective view of the empty driver/passenger seats equipped with the safety bar device of the present invention. 
       FIG. 6  is a perspective view of the occupied seats activating the safety bars under body weights of passengers not shown. 
       FIG. 7  is a perspective view of a seat activated safety bar device having optional side panels for privacy protection according to a second embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , common golf cart  1  has a seat  2  and armrests  3  fixed at opposite sides of a seat bottom  4  of the seat  2 , with the driver being located on the seat  2  near a steering wheel  5 , which may be either left-sided or right-sided. The cart has a frame unit  6  as well as wheels  7  mounted thereon in the manner common to golf carts. The cart  1  is driven by a gasoline engine or electrical motor not shown in the drawing. Also common to the typical golf carts are transmission gearing, an ignition system that connects a power source, such as a battery, of the drive motor of the cart and a breaking system, all of which are trimmed by a front fender  8  and a rear fender  9 . The golf cart  1  may also have a roof and support frame, which are not shown in the drawing. 
   The first embodiment of the golf cart seat-activated safety bar device  10  of the present invention is illustrated in  FIGS. 2 through 4 . The safety bar device  10  includes a pair of laterally adjacent driver/passenger seat bottoms  11   a  and  11   b  each having a front end  12  and a rear end  13 , which is pivotally connected thru a number of hinges  14  to a raised floor  15  of the golf cart. 
   In line with the hinges  14 , a number of leaf springs  16  also connect the rear ends  13  of the seat bottoms  11   a  and  11   b  to the floor  15  in order to assist the supported floatation of the same seat bottoms. 
   In  FIG. 3 , a weight rotor  20  is employed as a primary actuator to hold up the seat front  12  of the seat bottom  11   b  at rest until the seating passenger depresses it. The rotor  20  may be made of a heavy solid material such as metal and has a deep V-shaped notch  21  down to its center to provide an eccentric weight to a shaft  22  to which the rotor  20  is fixed. The rotor  20  and the shaft  22  are installed under the frame floor  15 . The rotor  20  may be also made of two or more components including a shell of the same profile and heavyweight filler such as concrete or other cementitious materials. 
   The rotor  20  may also comprise an elongated member that extends almost the entire length of the shaft in order to take up less diametrical space in the cart frame. Such elongated member gives an eccentric weight to the shaft  22 . 
   Two such shafts  22  are rotatably supported at their outer ends by a pair of metal brackets  23   a  and  23   b  angled to fit on the respective end walls of the floor  15  where they are fixed by fasteners  24 . An interior bracket  25  extending from a wall of the frame  15  supports the inner ends of the shafts  22 . 
   An articulated push bar  26  has a lower leg  27  fixed to the rotor  20  at its bottom end by one or more fasteners  28 . The leg  27  also has a top end connected to an upper arm  29  via an articulated connection. The push bar  26  extends through the frame floor  15  at an appropriate opening  30  shown in  FIG. 2 . 
   The arm  29  is fixed at its distal end to the bottom surface of the seat bottom  11   b  by a hinge  31 . 
   As shown in more detail in  FIGS. 3 and 4 , an elongated safety bar  32  is generally L-shaped and connected at its proximal end to an auxiliary weight arm  33 , which is in turn attached to the protruding end of the shaft  22 . As shown, the safety bar  32  is press fitted at its proximal end into a top slot  34  formed in a neck portion  35  of the arm  33 . A slit  36  formed at one or both sides of the neck portion  35  is to provide a resiliency of the arm  33  locally to allow the press fitting with the bar  32 . To secure the safety bar  32  in the neck portion  35 , a fastening screw may be threaded through the mating members. 
   The remainder of the safety bar  32  protrudes upward at rest in preparation for a passenger to board the cart. The safety bar has an upright position when the seat is in an upright propped position. The upright position is the neutral position. The safety bar lowers after a user sits in the seat. The lowered position is also called the engaged position, or seated position. 
   Because the bar  33  is attached off center of the axis of rotation  37  toward the center of gravity of the weight arm  33 , it acts positively to bias the safety bar  32  upright. The safety bar  32  has a length that extends across the cabin at least partially and a certain height above the top surface of the seat bottom  11   b  to support the torso of a passenger in a rough ride. 
   In this embodiment, the weight arm  33  is optionally installed as an auxiliary actuator to assist in holding up the seat front  12  at rest until the seating passenger depresses it. The arm  33  may be made of a heavy solid material such as metal and extends away from its axis of rotation  37  to provide an eccentric weight to activate the push bar  26 . The arm  33  may be also made of two or more components including a shell of the same profile and heavyweight filler such as concrete or other cementitious materials. 
   The weight arm  33  is rotatably supported at its bore formed transversely in a narrow heel  38  by the shaft  22  on the metal bracket  23   b . The narrow heel  37  is centered between two opposite side walls of the weight arm  33  so that the arm has symmetrical lateral profiles for installation at either side of the golf cart with a mere change of the correct pair of the bracket  23   a  or  23   b.    
   The bore of the weight arm  33  that grasps the shaft  22  may have a polygonal shape in cross section to ensure a non-rotating engagement between the arm  33  and the shaft  22 . Otherwise, they may be fit with each other via a dovetail connection. Or the safety bar  32  may be attached directly to the shaft  22  through its bore formed at right angle to the axis of the shaft  22 . 
   As long as the bar  32  is lightweight relative to the weight rotor  20  or the arm  33  and supportive of the moment of inertia of the torso of the boarding passenger in operation, it may be made of a variety of materials including wood, plastic or aluminum among others. 
   Therefore, when the safety bar device  10  is not activated the weight of the rotor  20  prevails to bias the push bar  26  upward raising the front end  12  of the seat bottom  11   a  or  11   b , which is also supported by the expanding leap springs  16  at the rear end  13  of the same seat bottom. At the same time, the resulting radial position of the shaft  22  maintains the safety bar  32  standing upright to clear a way for the passenger to enter the cart without an interference that is shown by the seat bottom  11   b  at the left side of  FIG. 2  and in  FIG. 3 . 
   In contrast, the seat bottom  11   a  at the right has been depressed by the passenger represented by a downward pressure P 1 , which depresses the push bar  26  against the weight bias of the rotor  20  and the spring bias  16  as well as the weight arm  33  if present. The safety bar  32  is lowered to a level, which limits the lateral outward movements of the passenger within the cabin of the golf cart which is shown at the right side of  FIG. 2  or in  FIG. 4 . The bar  32  at the seat bottom  11   a  now blocks the entrance or exit of that side of the cart to prevent an involuntary fallout of the passenger from the seat bottom  11   a.    
   Turning now to  FIGS. 5 and 6 , the safety bar device  10  is zoomed out for a general viewing of the operation from the preliminary position of the device in  FIG. 5  to the operational position of  FIG. 6 . 
   In  FIG. 5 , the seat bottoms  11   a  and  11   b  are complete with seat backs  40  with the seat bottoms suspended in equilibrium without the passengers. 
   However, when the passengers P 1  and P 2  take the seats as in  FIG. 6 , their weights prevail over the weight bias of the rotors  20  and the arms  33  and the spring bias discussed. Then, the safety bars  32  are lowered to a level, which limits the lateral outward movements of the passengers from the cabin of the golf cart. Although it is shown to install a pair of safety bar devices at opposite sides of the cart, the safety bar device at the driver side may be determined redundant due to the steering wheel as a support and thus left unguarded. 
     FIG. 7  shows a second embodiment of the present invention wherein the safety bar  32  is adapted to function as a frame for a protective side skirt or panel  41 . The side panel  41  is generally square and may be made of a light non-fabric or fabric material such as canvas to have a sleeve  42  along a side. The side panel  41  is tightly fitted over the length of the safety bar  32  at the sleeve  42  and such safety bar works as a privacy protection as well as a safety support for the passenger. When the bar  32  swivels back to the upright position, the panel  41  drapes down to reveal the access path to the seat. 
   As an alternate embodiment, an electrical motor can electrically control the safety bar, in conjunction with the mechanical means is mentioned above. An electrical motor shaft attached to the safety bar hinge can actuate the safety bar between a raised position and a lowered position. With the motor that can be actuated by a sensor switch, the electrical motor can lower the safety bar whenever a passenger is in seated position. The sensor switch may be a contact switch that cooperates with the movement of the seat. The electrical motor preferably has the same DC voltage as the vehicle DC voltage. It is preferred to include an electrical motor driven safety bar to allow smaller passengers such as children to be able to engage the safety mechanism. A manual electrical switch can be incorporated into the electrical motor assistance. The switch can raise and lower the safety bar allowing additional control, which would be helpful particularly for maintenance. 
   In lowered position, the safety bar optionally includes a locking mechanism to retain the safety bar in lowered position. The locking mechanism can be a clasp or clip that locks the safety bar into a safety bar slot. A slot can receive the free end of the safety bar and retain it in place until the user manually releases the locking mechanism to get out of the golf cart. 
   Therefore, while the presently preferred form of the golf cart seat activated safety bar device has been shown and described, and several modifications thereof discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims. 
   CALL OUT LIST OF ELEMENTS 
   
       
         1 : Golf Cart 
         2 : Seat 
         3 : Armrest 
         4 : Seat Bottom 
         5 : Steering Wheel 
         6 : Frame Unit 
         7 : Wheels 
         8 : Front Fender 
         9 : Rear Fender 
         10 : Safety Bar Device 
         11   a , 11   b : Seat Bottom 
         12 : Front End 
         13 : Rear End 
         14 : Hinge 
         15 : Frame Floor 
         16 : Leaf Spring 
         20 : Weight Rotor 
         21 : V-notch 
         22 : Shaft 
         23   a , 23   b : Metal Brackets 
         24 : Fasteners 
         25 : Interior Bracket 
         26 : Articulated Push Bar 
         27 : Lower Leg 
         28 : Fastener 
         29 : Upper Arm 
         30 : Opening 
         31 : Hinge 
         32 : Safety Bar 
         33 : Auxiliary Weight Arm 
         34 : Top Slot 
         35 : Neck Portion 
         36 : Slit 
         37 : Axis of Rotation 
         38 : Narrow Heel 
         40 : Seat Back 
         41 : Side Panel 
         42 : Sleeve