Abstract:
A starter system for racing vehicles such as sprint cars that enables the vehicle to be started while in position for a race without the need for a clutch or external means of generating forward motion.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of the prior filed, co-pending provisional application Ser. No. 60/315,760, filed Aug. 29, 2001. 

   FIELD OF THE INVENTION 
   This invention relates to an electrical starter system for a vehicle and more particularly to a cockpit-mounted starter system for a sprint car. 
   BACKGROUND OF THE INVENTION 
   A sprint car is a relatively small, open-wheel racing vehicle. The chassis is a lightweight tubular frame with a relatively short wheelbase. The sprint car has two small wheels in front and two large wheels in back. The back wheels are run with low pressure during a race, approximately 15 pounds, and are usually staggered in size to help hold the car on the banked track. Racing rules govern the size of the sprint car, the types of materials used to compose the vehicle, whether or not airfoils are allowed, and the size and power of the engine. 
   Because most sprint cars are composed of the same materials, constructed in a similar way and powered by similar engines, a significant factor to vehicle performance during a race is the overall weight of the vehicle. Sprint cars are, therefore, constructed so as to minimize weight. This includes using lightweight materials such as aluminum to construct the frame and other elements. In addition, sprint cars traditionally do not have a battery or starter. To start the engine, a sprint car must be pushed by a push truck or other vehicle to a relatively high rate of speed. While the sprint car is being pushed, the driver monitors the oil pressure, and when an optimum pressure is achieved, a switch is thrown allowing electric current to flow from a magneto to the engine spark plugs, thereby enabling combustion to initiate. 
   Another key factor determining performance is weight distribution. Sprint cars drivers have found it advantageous to distribute the weight of the vehicle towards the rear, thereby increasing traction, especially on a banked curve. Sprint car drivers who have incorporated starters in their sprint car design have faced the problem, not only of increased overall weight, but of increased forward weight in the engine compartment. 
   The present invention overcomes the above problems in the prior art by providing a new starter system so that a sprint car may be started without the use of a push truck. A flywheel of reduced size is provided to minimize weight increase and rotary inertia, and the starter is located rearward of the engine, preferably in the driver&#39;s compartment, thereby shifting weight distribution towards the rear of the vehicle. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a starter system for a sprint car thereby eliminating the need for push trucks or other external means of starting the engine, whereby the overall operation of sprint car racing is rendered more efficient and more suitable for televising. 
   Another object of the present invention is to provide a starter system for a sprint car which renders the operation of sprint car races safer for the drivers and track personnel by eliminating the need for push trucks on the track during a race. 
   Another object is to provide a starter system for a sprint car that may be easily installed with minimal adjustments or changes required to a common sprint car configuration. 
   Another object is to provide a starter system for a sprint car whereby the weight is distributed rearward of the engine compartment. 
   Still another object of the present invention is to provide a starter system for a sprint car wherein the flywheel is of reduced size, thereby minimizing weight, rotary inertia, and the space required to house the fly wheel. 
   Yet another object is to provide a compartment for housing the flywheel and starter pinion assembly whereby said assembly is protected from dirt, dust, debris and moisture while in operation. 
   In furtherance of the foregoing, the starter system includes a starter positioned in the driver&#39;s compartment, a battery connected to the starter for providing electric power to the starter motor, a flywheel positioned rearward of the engine compartment and forward of the cockpit, a crank shaft connecting the engine and the flywheel, and a drive shaft connecting the flywheel to the rear wheels of the vehicle, the starter having a pinion gear engageable with the flywheel for rotating the flywheel and starting the engine. The flywheel is of a reduced size to minimize the vehicle weight and to facilitate placement of the flywheel in a space provided between the engine block and cockpit. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagrammatic side elevational view of a sprint car. 
       FIG. 2  is an enlarged, partial, side view, cut away to reveal details of the starter mounted below the steering column and upwardly adjacent to the drive shaft. 
       FIG. 3  is an enlarged and simplified, partial, side elevation of the starter mounted to the rear engine wall, showing the crankshaft passing through an aperture in the rear engine mounting plate toward the cockpit, the flywheel attached to the crankshaft and located within the flywheel compartment, and the starter mounted to the starter mount plate. 
       FIG. 4  is an enlarged perspective view of the chassis, engine, flywheel, starter assembly, and cockpit of a sprint car showing the sprint car starter system in place in relation to the body of a sprint car. 
       FIG. 5  is an enlarged, partial, side elevation showing a portion of the drive-train assembly comprising the engine, crankshaft, flywheel, spacer, yoke assembly, and driveshaft. 
       FIG. 6  is a detailed perspective view of the starter mounting block showing a means for adjusting the engagement of the starter pinion to the flywheel. 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1-6 , a starter  40  is mounted in the driver&#39;s compartment (cockpit)  30  of a sprint car  100 , and a flywheel  4  is mounted on the engine crankshaft  19  such that the pinion  15  of the starter  40  engages the flywheel  4  thereby enabling the driver  32  to start the engine  9  by activating a switch (not shown) in the cockpit  30 . The starter  40  typically comprises a motor  41 , solenoid  42 , gear reduction assembly  43 , and pinion  15 . 
   Because of the novel positioning of the starter  40  within the cockpit  30  of the sprint car  100 , the starter  40  typically must be converted to left-hand rotation. This conversion may be accomplished by rewinding the starter armature using methods and materials commonly known to one skilled in the art. To develop the necessary torque to adequately turn the engine  9 , the starter motor  41  may include a gear reduction assembly  43  to increase the output torque. Production starter motors are available that afford various gear reductions, pinion choices and power ratings. These starters can be selected in conjunction with the flywheel starter gear and pinion to develop the most advantageous torque for the specific engine to which the starter system is applied. 
   The diameter of the crankshaft-mounted flywheel  4  should be within a range conducive to locating the flywheel  4  and starter pinion  15  within an area rearward of the engine  9 . For the sprint car starter system of the present invention, a flywheel diameter of 4½ to 10½ inches is preferable. The perimeter of the flywheel  4  is provided with gear teeth indexed to mesh with the teeth on the starter pinion  15 . In the preferred embodiment the flywheel  4  has a 10 diametral pitch and approximately an 8½ inch outer diameter. The flywheel  4  is typically attached to the crankshaft  19  by means of a crankshaft flange  56  typically provided with an engine  9 . 
   As shown in  FIG. 5 , a spacer  52  is attached to the rearward side of the flywheel  4  to move the mounting point of a U-joint flange  53  rearward. The spacer  50  may incorporate gear teeth (not shown) to engage timing belts or gears to power pumps or other devices, (e.g., power steering, fuel and oil pumps). The U-joint flange  53  for the U-joint/yoke assembly  50  (see elements numbered  51 ,  53 , and  55 ) is then attached with through-bolts that fasten the flywheel  4 , spacer  52 , and yoke assembly  50  to the back of the crankshaft  19 . Dashed lines in  FIG. 5  indicate the approximate position of holes  54  that contain the through-bolts after assembly. 
   The rear motor mount plate  1  is attached to the chassis  10  at the front cockpit frame rails  25  and  26 . The horizontal front cockpit frame rails are shown in cross-section in  FIGS. 2 and 3  and designated by the numbers  25  and  26 . The vertical frame rails are not shown but connect the ends of rails  25  and  26  to form a rectangular frame. The starter mount plate  5  is placed inside the cockpit  30  on the rearward side of the front cockpit frame rails  25  and  26 . The cockpit frame rails, rear motor mount plate  1 , and starter mount plate  5  define a flywheel compartment located between the engine  9  and the cockpit  30 , in which the flywheel  4  and starter pinion  15  are contained. Spacers  21 ,  22 , and  23  (indicated by dashed lines in  FIG. 4 ) may be placed between the rear motor mount plate  1  and the starter mount plate  5  to stabilize the plates. 
   The engine  9  is placed into the chassis  10 , positioning the flywheel  4  through and behind the rear motor plate  1 . The torque tube housing  12 , which is machined so as to position the torque ball  14  at the yoke assembly pivot point  55 , is attached on the cockpit side of the starter mount plate  5 . The torque ball  14  and retaining ring  13  are placed over the torque tube  8 . The driveshaft  3  is then splined and inserted into the U-joint yoke  51 . Through-bolts  24  fasten the starter mount plate  5 , the chassis frame rails  10 , mounting plate spacers  21 ,  22  and  23 , if included, and the rear motor mount plate  1  to the engine block  9 . A front motor mounting plate (not shown) is then bolted to the chassis  10  and the engine  9  using through-bolts at the front of the engine  9 . Front mounting plate spacers (not shown) may be included in this front motor mount assembly, if necessary. The torque ball  14  is then secured within the torque tube housing  12  using the torque tube retaining ring  13 . 
   A starter solenoid  42  is mounted in proximity to the starter motor  41  and is operated by a known type of starter control circuit. The solenoid  42  is connected to a pinion  15  for sliding the pinion  15  a predetermined distance to engage the pinion gear with the flywheel  4 . The starter motor  41  and solenoid  42  are mounted on the cockpit side of the starter mount plate  5 , to the right and upwards of the torque tube housing  12 . A starter mounting block  2  is fastened to the starter mount plate  5  within the cockpit  30 . The starter mounting block  2  may incorporate adjustment screws, or jack bolts and shims, to adjust the pinion-to-flywheel radial depth and the pinion engagement depth. 
   The starter  40  may be mounted at a location usually occupied by a vehicle fuel pump (not shown). In one embodiment, the fuel pump is moved to a location forward of the rear motor mount plate  1 , thereby reducing driver  32  exposure to fuel under pressure.  FIG. 2  is an enlarged, partial, side view, cut away to reveal details of the starter  40  mounted below the steering column  7  (see also FIG.  4 ). A sprint car wheel  16  is shown in phantom lines. 
   In  FIG. 6 , an example of an operable mounting block is designated as  2 . The starter mounting block has a large central hole  44  to receive the starter pinion  15 . Starter mounting holes  45  are provided so that the starter  40  may be bolted onto the starter mounting block  2 . The starter mounting block  2  is fastened to the starter mount plate  5  using three bolts  47  fitted into slots  49 , and a fourth pivot bolt  48  fitted into a circular hole (not shown). When adjustment screws  46  are rotated, they alter the position of the bolts  47  within the slots  49  by moving the mounting block  2  around a pivot point formed by the fourth pivot bolt  48 . Moving the mounting plate in this manner adjusts the position of the pinion  15  relative to the flywheel  4 . 
   The starter  40  is then connected, using appropriate wiring, to a battery  6  located underneath the driver&#39;s seat  11 . A switch (not shown) is provided with the starter wiring assembly and is mounted within the cockpit  30 . This cockpit mounting location places the starter  40  and associated electrical components in a location where they are less exposed to dirt, dust and moisture from the track, and where they can be easily serviced. 
   When the starter  40  is in operation the solenoid  42  is activated, thereby extending the pinion  15  such that it engages the flywheel  4 . The flywheel  4  incorporates a ring rear on its outer periphery. The pinion  15  of the starter  40  is engaged with the ring gear of the flywheel  4  for driver-initiated electric starting of the engine  9 . The engagement of the pinion  15  to the flywheel  4  may be adjusted using adjustment screws on the starter mounting block  2 . 
   The starter motor  41  turns the pinion  15 , which rotates about an axis  18  turning the flywheel  4 . The flywheel  4  turns the crankshaft  19  (and driveshaft  3  if engaged), which rotates about axis  17 . The crankshaft  19  moves the associated engine components causing the engine to start in a manner known to one skilled in the art. When the electrical supply to the starter motor  41  is stopped, the solenoid  42  is no longer activated and the pinion  15  recedes into its housing, thereby disengaging the pinion  15  from the flywheel  4  during normal engine operation. 
   It should be appreciated that the starter system of the present invention provides a means for starting a sprint car  100  without the need for a push truck or other external source of power, while distributing the weight of the starter system rearward of a conventional starter assembly. By locating the starter  40  within the cockpit  30 , not only is weight shifted rearward, but the starter system is less exposed to the elements. The location of the starter  40  within the cockpit  30  allows sufficient room for the driver  32  to operate. The flywheel  4  is mounted at the rear of the engine rather than the front, further distributing weight towards the rear. By eliminating the need for push trucks, this starter system makes sprint car racing safer and more suitable for televising.